Chronic Myeloproliferative Neoplasms Research Articles

Central Retinal Vein Occlusion as the Debut of a Chronic Myeloproliferative Neoplasm

Introduction. Most retinal vascular diseases are associated with systemic risk factors such as hypertension, diabetes mellitus, age and smoking. However, in their absence, further examination is required to identify possible hematological disorders.Purpose. Improve the diagnostic and management scheme for patients with occlusion of the central retinal vein or its branches.Materials and methods. A clinical case of the onset of polycythemia vera with the central retinal vein occlusion is described. As part of the study, a molecular genetic analysis was carried out to identify the driver mutation JAK2V617F in peripheral blood as a screening diagnosis of Ph-negative chronic myeloproliferative neoplasms (CMN), a cytological, cytogenetic study of bone marrow aspirate and a morphological study of bone marrow trephine biopsy.Results. A mutant allele of the JAK2V617F gene with a diagnostically significant allele load of 14.61 % was determined in a patient hospitalized in the ophthalmology department with a diagnosis of central retinal vein occlusion (CRVO) of the right eye. The patient was referred for further examination to the Moscow City Hematology Center of Botkin City Clinical Hospital, where, aſter examination, the diagnosis was established: True polycythemia.Discussion. CMN are a group of tumor diseases of hematopoietic tissue characterized by malignant transformation of bone marrow stem cells with their subsequent clonal proliferation. Cytogenetic and molecular genetic disorders play a significant role in the pathogenesis of chronic CMN. True polycythemia, essential thrombocytemia, primary myelofibrosis belong to the group of classical Ph-negative CMP, Thrombotic, vascular and hemorrhagic complications are the most common causes of death in patients with this pathology.Conclusion. Previously, various ophthalmological manifestations and symptoms have been described in patients with CMN. The observed complications are diverse and oſten secondary to the pathognomonic hematological disorders for these diseases. It is worth considering the clinical value of molecular genetic analysis to detect the JAK2V617F mutation in patients with central retinal vein occlusion for early diagnosis of CMN and timely administration of appropriate therapy.

Retinal Vessel Analysis and Microvascular Abnormalities in Patients with Philadelphia-Negative Chronic Myeloproliferative Neoplasms.

Background: Philadelphia-negative chronic myeloproliferative neoplasms are a group of clonal hematopoietic disorders including polycythemia vera, essential thrombocythemia, and primary myelofi-brosis. These neoplasms are characterized by an increased risk of thrombotic complications. Several studies have highlighted that the study of vessels of the retina offers the opportunity to visualize, in vivo, the damage to microcirculation that is common in various systemic pathologies. Methods: in our study, forty patients underwent an ophthalmological examination, using non-invasive imaging tech-niques, for analyses of their retinal vascularization. The objective was to correlate the findings ob-tained from this study of the retina with different markers of thrombotic risk, to demonstrate the usefulness of studying retinal vessels as a possible new prognostic biomarker of thrombotic risk in patients affected by Philadelphia-negative chronic myeloproliferative neoplasms. Results: retinal imaging demonstrated changes in the microcirculation, with a reduced vascular density of the deep and superficial capillary plexuses with respect to a normal group, and a correlation between retinal changes and blood parameters. Conclusions: additional research will allow us to determine whether retinal changes in individuals with chronic myeloproliferative neoplasms could be predictive of the development of thrombotic events in these subjects.

Paroxysmal Nocturnal Hemoglobinuria and Primary Myelofibrosis as an Extremely Rare Combination of Clonal Hematological Diseases: A Literature Review and Two Clinical Case Reports

The combinations of paroxysmal nocturnal hemoglobinuria (PNH) and chronic myeloproliferative neoplasms (CMPNs) are extremely rare. All of them refer to clonal hematological diseases and are characterized by high thrombosis risk, which most commonly causes death. This paper provides literature data on 38 combined cases of PNH and Ph-negative/Ph-positive CMPNs mainly in the “case report” format, taken from 22 sources published in 1970–2022. Additionally, the paper reports personal experience with 2 combined cases of PNH and primary myelofibrosis (PMF/PNH) from the archive of the Moscow Municipal Center for Hematology (SP Botkin City Clinical Hospital).

Chronic Myeloproliferative Neoplasms and Sodium-Glucose Co-Transporter-2 Inhibitors: A Case Series.

Chronic Myeloproliferative Neoplasms and Sodium-Glucose Co-Transporter-2 Inhibitors: A Case Series.

Chronic myeloproliferative neoplasms with concomitant CALR mutation and BCR::ABL1 translocation: diagnostic and therapeutic implications of a rare hybrid disease.

Myeloproliferative neoplasms (MPNs) are subdivided into Philadelphia (Ph) chromosome-positive chronic myeloid leukemia (CML) and Ph-negative MPNs. BCR::ABL1 translocation is essential for the development and diagnosis of CML; on the other hand, the majority of Ph-negative MPNs are characterized by generally mutually exclusive mutations of Janus kinase 2 (JAK2), calreticulin (CALR), or thrombopoietin receptor/myeloproliferative leukemia (MPL). CALR mutations have been described essentially in JAK2 and MPL wild-type essential thrombocythemia and primary myelofibrosis. Rarely coexisting CALR and MPL mutations have been found in Ph-negative MPNs. BCR::ABL1 translocation and JAK2 mutations were initially considered mutually exclusive genomic events, but a discrete number of cases with the combination of these genetic alterations have been reported. The presence of BCR::ABL1 translocation with a coexisting CALR mutation is even more uncommon. Herein, starting from a routinely diagnosed case of CALR-mutated primary myelofibrosis subsequently acquiring BCR::ABL1 translocation, we performed a comprehensive review of the literature, discussing the clinicopathologic and molecular features, as well as the outcome and treatment of cases with BCR::ABL1 and CALR co-occurrence.

Chronic Myeloid Leukemia Presenting with Megakaryocytic Blast Crisis: a Case Report with a Favorable Outcome

Chronic myeloid leukemia (CML) belongs to the chronic myeloproliferative neoplasms, a clonal disorder of pluripotent hematopoietic stem cells, arising because of a hallmark genetic anomaly- reciprocal translocation between chromosomes 9 and 22, known as the Philadelphia chromosome, which generates the BCR::ABL fusion gene. The disease can have a biphasic/triphasic evolution, comprised of an accelerated phase and a terminal blast phase (usually biphasic when blastic phase is lymphoid in nature). Most cases present during the chronic phase of the disease, with only 10% of cases presenting in the blast phase. Megakaryocytic blast crisis is an unusual form of presentation, accounting for less than 3% of cases and it commonly carries an unfavorable prognosis compared to the classic myeloid, lymphoid or even mixed lineage blast crises. Aim: To bring forth an unusual case of CML presenting with megakaryocytic blast crisis and the therapeutic challenges associated with this particular presentation, unexpectedly ending with a favorable outcome. Matherial and methods: we hereby present the case of a 50 year old female patient, diagnosed in 2015 with CML- megakaryocytic blast crisis, who underwent treatment with a tyrosine kinase inhibitor (TKI)- imatinib and intensive chemotherapy regimen 3+7, without satisfactory response. A second induction chemotherapy regimen followed (MEC), alltogether with the same TKI and cytoreductive treatment (hydroxyurea/HU), but still without achieving a complete remission. Thus, the TKI was switched to dasatinib and complete normalisation of blood counts followed (including thrombocytes). However, there was still inadequate molecular and cytogenetic response. Therefore, TKI dosage was increased and after 4 months the patient achieved complete remission, with no detectable BCR::ABL transcript. She spent 9 years on the same TKI until important pleural effusion developed, which required switching to another 2nd generation TKI- bosutinib, based on the patients age, genetic profile and commorbidities. She is still in complete remission without detectable BCR::ABL transcript/Philadelphia chromosome to this day (2024). Results and conclusions: this is the case of a rare presentation of CMLmegakaryocytic blast crisis, who underwent both TKI and intensive chemotherapy induction regimens, marked by a favorable unexpected outcome.

First inter-institutional consensus on Chronic Myeloproliferative Neoplasms.

The objective of the consensus is to make available to the professionals of the different public health institutions in our country, who are in charge of these diseases, the most relevant and up-to-date information about their diagnosis and treatment in clinical practice. With this inter-institutional consensus we hope to contribute to improving the quality of care for patients with chronic myeloproliferative neoplasms throughout the Mexican Republic, to unify criteria in both diagnosis and treatment of the different myeloproliferative diseases.

Essential thrombocythaemia.

Essential thrombocythemia (ET) is a chronic Philadelphia-negative myeloproliferative neoplasm that has its main involvement in the megakaryopoietic lineage, generating sustained thrombocytosis in peripheral blood and an increase in the number of mature megakaryocytes in the bone marrow. In addition to marked thrombocytosis, it is characterized by increased thrombotic or hemorrhagic risk and the presence of constitutional symptoms. Patients with ET have a low but known risk of disease progression to myelofibrosis and/or acute leukemia. The diagnosis is made based on the 2016 WHO criteria. At present, available treatments for patients with ET are mainly aimed at minimizing the risk of thrombosis and/or bleeding.

Rusfertide, a Hepcidin Mimetic, for Control of Erythrocytosis in Polycythemia Vera

BackgroundPolycythemia vera is a chronic myeloproliferative neoplasm characterized by erythrocytosis. Rusfertide, an injectable peptide mimetic of the master iron regulatory hormone hepcidin, restricts the availability of iron for erythropoiesis. The safety and efficacy of rusfertide in patients with phlebotomy-dependent polycythemia vera are unknown.MethodsIn part 1 of the international, phase 2 REVIVE trial, we enrolled patients in a 28-week dose-finding assessment of rusfertide. Part 2 was a double-blind, randomized withdrawal period in which we assigned patients, in a 1:1 ratio, to receive rusfertide or placebo for 12 weeks. The primary efficacy end point was a response, defined by hematocrit control, absence of phlebotomy, and completion of the trial regimen during part 2. Patient-reported outcomes were assessed by means of the modified Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) patient diary (scores range from 0 to 10, with higher scores indicating greater severity of symptoms).ResultsSeventy patients were enrolled in part 1 of the trial, and 59 were assigned to receive rusfertide (30 patients) or placebo (29 patients) in part 2. The estimated mean (±SD) number of phlebotomies per year was 8.7±2.9 during the 28 weeks before the first dose of rusfertide and 0.6±1.0 during part 1 (estimated difference, 8.1 phlebotomies per year). The mean maximum hematocrit was 44.5±2.2% during part 1 as compared with 50.0±5.8% during the 28 weeks before the first dose of rusfertide. During part 2, a response was observed in 60% of the patients who received rusfertide as compared with 17% of those who received placebo (P=0.002). Between baseline and the end of part 1, rusfertide treatment was associated with a decrease in individual symptom scores on the MPN-SAF in patients with moderate or severe symptoms at baseline. During parts 1 and 2, grade 3 adverse events occurred in 13% of the patients, and none of the patients had a grade 4 or 5 event. Injection-site reactions of grade 1 or 2 in severity were common.ConclusionsIn patients with polycythemia vera, rusfertide treatment was associated with a mean hematocrit of less than 45% during the 28-week dose-finding period, and the percentage of patients with a response during the 12-week randomized withdrawal period was greater with rusfertide than with placebo. (Funded by Protagonist Therapeutics; REVIVE ClinicalTrials.gov number, NCT04057040.)

Neutrophil-to-lymphocyte ratio and all-cause mortality with and without myeloproliferative neoplasms—a Danish longitudinal study

The neutrophil-to-lymphocyte ratio(NLR) is increased in chronic inflammation and myeloproliferative neoplasms (MPN). We hypothesize that NLR is associated with all-cause mortality and mortality by comorbidity burden in the general population and individuals with MPN. We included 835,430 individuals from The Danish General Suburban Population Study, general practitioners, and outpatient clinics. We investigated NLR on mortality stratified by prevalent and incident MPN, essential thrombocythemia (ET), polycythemia vera (PV), myelofibrosis (MF), comorbidity burden (CCI-score), and the Triple-A risk score using hazard ratio (HR) and 95% confidence interval (95%CI). NLR 1–1.9 was the reference level. During a median follow-up of 11.2 years, 197,802 deaths were recorded. All-cause mortality increased for a stepwise increasing NLR with a HR (95%CI) for NLR ≥ 6 of 2.06(2.03–2.09) for the whole population and 2.93(2.44–3.50) in prevalent MPN. ET, PV, and MF had a HR (95%CI) for NLR ≥ 2 of 2.14(1.71–2.69), 2.19(1.89–2.54), and 2.31(1.91–2.80). Results were similar for incident MPN. Mortality was higher for stepwise increasing NLR and CCI-score(pinteraction < 2×10–16), with a HR for NLR ≥ 6 of 2.23(2.17–2.29), 4.10(4.01–4.20), and 7.69(7.50–7.89), for CCI-score 0, 1–2, or ≥3. The Triple-A risk score demonstrated alignment with NLR. Increasing NLR and comorbidity burden were associated with lower survival in individuals without MPN but were even worse in prevalent and incident MPN, ET, PV, and MF.

In silico trial for the assessment of givinostat dose adjustment rules based on the management of key hematological parameters in polycythemia vera patients.

Polycythemia vera (PV) is a chronic myeloproliferative neoplasm characterized by excessive levels of platelets (PLT), white blood cells (WBC), and hematocrit (HCT). Givinostat (ITF2357) is a potent histone-deacetylase inhibitor that showed a good safety/efficacy profile in PV patients during phase I/II studies. A phase III clinical trial had been planned and an adaptive dosing protocol had been proposed where givinostat dose is iteratively adjusted every 28 days (one cycle) based on PLT, WBC, and HCT. As support, a simulation platform to evaluate and refine the proposed givinostat dose adjustment rules was developed. A population pharmacokinetic/pharmacodynamic model predicting the givinostat effects on PLT, WBC, and HCT in PV patients was developed and integrated with a control algorithm implementing the adaptive dosing protocol. Ten in silico trials in ten virtual PV patient populations were simulated 500 times. Considering an eight-treatment cycle horizon, reducing/increasing the givinostat daily dose by 25 mg/day step resulted in a higher percentage of patients with a complete hematological response (CHR), that is, PLT ≤400 × 109 /L, WBC ≤10 × 109 /L, and HCT < 45% without phlebotomies in the last three cycles, and a lower percentage of patients with grade II toxicity events compared with 50 mg/day adjustment steps. After the eighth cycle, 85% of patients were predicted to receive a dose ≥100 mg/day and 40.90% (95% prediction interval = [34, 48.05]) to show a CHR. These results were confirmed at the end of 12th, 18th, and 24th cycles, showing a stability of the response between the eighth and 24th cycles.

Co-occurrence of JAK2-V617 F mutation and BCR::ABL1 translocation in chronic myeloproliferative neoplasms: a potentially confounding genetic combination.

Myeloproliferative neoplasms (MPNs) are classified into Philadelphia (Ph) chromosome-positive chronic myeloid leukemia (CML) and Ph-negative MPNs. BCR::ABL1 translocation is the key genetic event of CML, whereas JAK2/MPL/CALR mutations are molecular aberrations of Ph-negative MPNs. Despite initially considered mutually exclusive genetic aberrations, the co-occurrence of BCR::ABL1 and JAK2 has been reported in a limited number of cases. The two genetic alterations may be identified either at the same time or JAK2 aberration may be detected in patients with a previous CML treated with tyrosine kinase inhibitors or, finally, BCR::ABL1 translocation occurs in patients with a history of JAK2-positive MPN. This combination of genomic alterations is potentially confounding with clinical manifestations often misinterpreted either as disease progression or drug resistance, therefore leading to inappropriate patient's treatment. Our systematic review aims to improve hematologist and pathologist knowledge on this rare subset of patients. Starting from the presentation of two additional cases from our routine daily practice, we focus mainly on clinical, laboratory, and bone marrow histological findings, which may represent useful clues of BCR::ABL1 and JAK2 co-occurrence. The interaction between JAK2 and BCR::ABL1 clones during the disease course as well as therapy and outcome are presented.

Polycythemia vera and management of the thrombotic risk: an update

Polycythemia vera (PV) is a chronic Philadelphia-negative myeloproliferative neoplasm caused by JAK2 mutation and characterized predominantly by the overproduction of red blood cells. The current treatment strategies of PV are based on periodic phlebotomies aimed at preventing thrombotic events associated with increased hematocrit levels. Additional therapies to mitigate the thrombotic burden, which represents the most important predictor of reduced survival in PV patients, include cytoreductive therapies, low-dose aspirin, and systemic anticoagulation. This concise review summarizes the current knowledge on the management of the thrombotic risk in PV patients.

JAK2, CALR, and MPL Mutation Profiles in Colombian patients with BCR-ABL Negative Myeloproliferative Neoplasms.

Among the chronic myeloproliferative neoplasms (MPNs) not associated with BCR-ABL mutations are polycythemia vera, primary myelofibrosis, and essential thrombocythemia. These diseases are caused by mutations in genes, such as the JAK2, MPL, and CALR genes, which participate in regulating the JAK-STAT signaling pathway. This study aimed to establish the frequencies of mutations in the JAK2, MPL, and CALR genes in a group of Colombian patients with a negative clinical diagnosis of BCR-ABL chronic myeloproliferative neoplasms. The JAK2 V617F and MPL W515K mutations and deletions or insertions in exon 9 of the CALR gene were analyzed in 52 Colombian patients with polycythemia vera, primary myelofibrosis, and essential thrombocythemia. The JAK2V617F mutation was carried by 51.9% of the patients, the CALR mutation by 23%, and the MPL mutation by 3.8%; 23% were triple-negative for the mutations analyzed. In these neoplasms, 6 mutation types in CALR were identified, one of which has not been previously reported. Additionally, one patient presented a double mutation in both the CALR and JAK2 genes. Regarding the hematological results for the mutations, significant differences were found in the hemoglobin level, hematocrit level, and platelet count among the three neoplasms. Thus, this study demonstrates the importance of the molecular characterization of the JAK2, CALR and MPL mutations in Colombian patients (the genetic context of which remains unclear in the abovementioned neoplasms) to achieve an accurate diagnosis, a good prognosis, adequate management, and patient survival.

Correlation of TCR Repertoire Diversity with Myeloid Gene Mutations in Chronic and Advanced Phase Myeloproliferative Neoplasms

Introduction: Myeloproliferative neoplasms (MPN) are characterized by a chronic phase (CP), with indolent clinical behavior and, in 10-30% of cases, progression to advanced phases (AP), with aggressive behavior and compromised prognosis. Numerous factors have been associated with progression to AP, including the acquisition of mutations in recurrently mutated myeloid genes (1,2). On the other hand, decreased diversity in the T-cell receptor (TCR) repertoire has been associated with worse prognosis in solid tumors. The purpose of this work is to study the correlation between the acquisition of mutations in myeloid genes and the diversity of the TCR repertoire in chronic and advanced myeloproliferative neoplasms. Methods: Patients with chronic CP and AP myeloproliferative neoplasms were selected. The selected patients underwent an NGS panel of 48 myeloid genes. Only pathogenic (P) or likely pathogenic (LP) variants were considered. In parallel, the study of the TCR repertoire by NGS with the panel “AmpliSeq for Illumina Immune Repertoire Plus, TCR beta Panel” (Illumina™) was performed on the available samples. Finally, the obtained data were correlated. The study was approved by the local ethics committee. Results: A total of 22 patients were selected, 10 in CP and 12 in AP. Regarding diagnosis, 8 were polycythemia vera (PV), 4 essential thrombocythemia (ET), 6 secondary myelofibrosis (MFS) (1 to PV and 5 to ET), 2 systemic mastocytosis (MS) and 1 primary myelofibrosis (MFP). Eighty percent were male and the mean age was 68 years. The AP patients were significantly older (74 vs. 62 years of age, p&amp;lt;0,001). Regarding the myeloid NGS panel result, 41 mutations were found in 19 patients. Fourteen percent of the patients had no mutation, 36% had an isolated driver mutation and 50% had additional mutations. Of these, 9% were in CP and 81% were in AP. The most recurrently mutated genes were JAK2 (45.4%), CALR (18.2%), ASXL1, IDH2, SRSF2, IDH2 (all 13.6%), MPL and KIT (both 9.1%). Regarding the results of the TCR repertoire, it was possible to perform the study in 11 patients, 4 in CP and 7 in AP. Only 6/11 had results of sufficient quality to allow analysis. Of these 6 patients, 3 were in CP and 3 in AP. As can be seen in Figure 1, the diversity of the TCR between CP patients and PC patients was different. Thus, while the pattern of diversity in the CP phase shows the expected distribution, the diversity in AP shows a characteristic pattern. Conclusions: APs of MPNs show an abnormal TCR diversity pattern. This pattern may be related to the acquisition of myeloid gene mutations in AP. To our knowledge, this is the first study demonstrating an alteration in TCR diversity in AP and opens the door to future fields of research.

Risk Factors for Thrombosis in Essential Thrombocythemia: A Clinico-Pathological Study of 138 Patents in a Middle Eastern Population

Background: Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm (MPN) characterized by clonal proliferation of megakaryocyte lineage. Natural history of ET is characterized by cardiovascular events (thrombosis) along with bleeding, transformation to myelofibrosis (MF), and acute myeloid leukemia (AML). There is paucity of data in ET patients from the Arab World. We aimed to study the risk factors for thrombosis and clinical course of ET in a cohort of 138 patients in a Middle Eastern population. Methods: The study was approved by the institutional review board. All patients aged 16 or over, diagnosed with ET and followed at our center from January 2003 till June 2022, were included. Diagnosis was based on 2017 World Health Organization Classification diagnostic criteria. We gathered data on baseline clinical and laboratory characteristics from the electronic medical records and patients' files. Hematologic parameters (platelet counts, leukocyte counts, hemoglobin, and mean platelet volume [MPV]) at the time of diagnosis were retrieved and information on cardiovascular events and complications (arterial and venous thrombotic events) along with progression to myelofibrosis, acute myeloid leukemia, need for cytoreductive therapy, and control of platelet count were recorded. Multivariate regression model was used to determine the independent significant factor(s) for thromboembolism with corresponding odds ratio and 95% confidence intervals. A P-value of ≤0.05 was considered significant. Results: A total of 138 patients were included in the study. Median age of the cohort was 47 (range, 16-84) years at the time of diagnosis with 73 (52.9%) females. JAK2 V617F mutation was present in 53 (38.4%) patients, CALR in 21 (15.2%), MPL in 43 (31.2%), and 21 (15.2%) patients were triple negative. All the patients with MPL mutation had Pro106Leu mutation. After a median follow up of 5 (range 1-26) years, 31 (22.5%) patients had vascular events, 16 (51.5%) had arterial events, 13 (42%) had venous thrombosis, 4 had both arterial &amp; venous events, while 2 patients had transient ischemic attacks. Nine (6.5%) patients progressed to MF, and 5 (3.6%) to AML. Ten (7.25%) patients died, 4 due to MF or AML related and 6 due to other causes. High IPSET score was strongly associated with thrombosis (P ˂0.001). High MPV and uncontrolled (high) platelet count were associated with the risk of thrombosis in univariate analysis (P 0.006 and &amp;lt;0.001, respectively) and there was a trend towards increased risk of thrombosis in patients with high MPV and uncontrolled platelet count (P 0.061 and 0.09, respectively) in multivariate analysis. Conclusions: Our ET patient population had high prevalence of MPL (Pro106Leu) mutation which may be germ line in nature as previously reported, and correspondingly lowered the prevalence of JAK2V617F and CALR mutations in our cohort. Thrombosis developed in 26.8% patients. In multivariate analysis, a high IPSET score was strongly associated with thrombosis. There was a trend towards increased risk of thrombosis with high MPV and uncontrolled (high) platelet count. This study may help better understand the biology of ET in this population.

Prevalence of Second Cancers in Patients with Polycythemia Vera (PV): A Retrospective Analysis of US Real-World Claims Data

Background:Polycythemia vera (PV) is a chronic myeloproliferative neoplasm (MPN) associated with risk of leukemic or fibrotic progression (Tefferi and Barbui. Am J Hematol. 2017;92;94-108). In addition to the known risk of disease transformation, patients with MPNs have a 60% higher risk of developing second non-hematologic cancers compared to matched controls. Skin cancers are among the most prevalent second cancers, with a reported 2.8-fold increase in risk of non-melanoma skin cancer (NMSC) (Landtblom et al., Leukemia. 2018;32:2203-10). The inherent risk associated with MPNs is exacerbated by cytoreductive treatments, as patients treated with hydroxyurea (HU) were found to have a two-fold higher risk of NMSC compared to patients who were not treated with HU (Barbui et al., Leukemia. 2019;33:1996-2005). Previous studies examined fewer than 2000 patients; the study populations may have included patients with other MPNs and PV. Our objective was to evaluate the frequency of second cancers in patients with a primary PV diagnosis who were treated with HU compared to phlebotomy only using a large US real-world claims database. Methods:This real-world, retrospective cohort study used Optum's deidentified Market Clarity Data consisting of electronic health records (EHR) on 105 million US patients and linked medical and prescription claims between 1/1/2007 to 12/31/2019. More than 82,000 patients with ≥1 PV diagnosis at any time were identified within the extracted dataset. For this analysis, eligible patients were ≥18 years old and required ≥2 PV diagnosis codes with ≥60 days between the first and last diagnosis code in the data period. Patients were indexed at the first diagnosis code of PV preceded by ≥1 year of EHR data (“index”) and required ≥1 year of post-index data or death prior to data period end. Patients with a pre-index diagnosis of secondary polycythemia, leukemia, myelodysplastic syndrome, myelofibrosis, or stem cell transplant were excluded. Second cancers were identified at first occurrence of a diagnosis code for a defined cancer in EHR during specified time periods. Analysis of post-treatment cancer rates used a subset of patients with pre-index medication data and excluded cancer types identified prior to treatment. Results:The total study cohort included 20,089 patients with PV (mean age, 63.0 years; 57.8% male; 88.6% Caucasian). Some patients (15.5%; n=3112) had evidence of a pre-index cancer. Median duration of follow-up was 4.3 years (IQR, 2.4-5.9). Among the total cohort, 35.7% (7181 patients) reported at least one second cancer in the post-index period (“post-index period prevalence”). The rate of second cancers in the post-index period was 109.7 events per 1000 patient years (PY). The most common non-hematologic malignancies were skin cancers (22.1/1000 PY) followed by prostate cancer (8.1/1000 PY) and breast cancer (6.7/1000 PY) (Figure 1). Within the total cohort, 9.1% (1830 patients) reported at least one skin cancer in the post-index period, with 8.3% (1659 patients) experiencing NMSC and 1.4% (286 patients) experiencing melanoma (Figure 1). The post-index period prevalence rate of NMSC was 6 times higher vs. the rate of melanoma (19.8 vs. 3.3/1000 PY). Among NMSCs, the rate of basal cell carcinoma was higher than the rate of squamous cell carcinoma (8.7 vs. 6.9/1000 PY). However, the highest rate was observed for non-specific or unspecified malignant neoplasms (8.9/1000 PY). Within a subset of 17,402 patients with pre-index medication data, 20.2% (n=3512) were exposed to at least 4 weeks of HU (without ruxolitinib) at any time; 19.0% (n=3314) were treated with phlebotomy (PHL) only. The rate of any second malignancy subsequent to treatment was &amp;gt;2.5-times higher in the HU vs. PHL group (140.4 vs. 55.3/1000 PY) (Table 1). Rates of skin cancers were nearly two times higher in the HU vs. PHL group for any skin cancer (31.6 vs. 17.7/1000 PY), NMSC (28.9 vs. 15.7/1000 PY), and melanoma (4.5 vs. 2.9/1000 PY). Conclusion:To our knowledge, this is the largest retrospective study evaluating the frequency of second cancers in a cohort of US patients with PV to-date. We found that patients with PV had high rates of malignancies associated with their primary PV diagnosis. The highest rates were observed for skin cancers, driven by the frequency of NMSC. Patients treated with HU had nearly twice the rate of skin cancers (including NMSC and melanoma) compared to PHL-only treated patients.

Promise: Investigation into the Combination of a Potent Beti with Ruxolitinib in Patients with High or Intermediate-2 Risk Myelofibrosis Not Receiving an Adequate Response with Ruxolitinib Alone

ISRCTN: 12451433 Background: Myelofibrosis (MF), a chronic myeloproliferative neoplasm (MPN), often results in progressive splenomegaly and cytopenia (1). Acute myeloid leukaemia develops in 10-20% of patients, and median survival with intermediate-2 disease is four years (2). Stem cell transplant can be curative, but is only suitable for younger, comorbidity-free patients (median MF diagnosis is 73.6 years) (3). Janus Kinase 2 (JAK2) mutation is common in MPN, and the JAK1/2 inhibitor ruxolitinib was approved in 2011 (4). However, patients still experience high disease burden, with a clear need for further treatments. Research has now focused on bromodomain and extra terminal (BET) inhibitors (5), in particular the role these have in disease associated inflammation (6). Preclinical data suggests BETi disrupts this inflammation leading to anti-fibrotic activity within MPN models. BETi with ruxolitinib eliminates fibrosis in MF mouse models thus overcoming a limitation of ruxolitinib monotherapy (7). OPN-2853 (previously PLX2853) is potent against isolated bromodomains from multiple BET proteins with rapid drug absorption, high Cmax, and short half-life differentiating it from other BETi. Preclinical efficacy has been demonstrated across a range of hematologic malignancies. PROMise is evaluating OPN-2853 in combination with ruxolitinib to identify the recommended phase 2 dose (RP2D). Methods: Primary Objectives: To assess the RP2D of OPN-2853 in combination with ruxolitinib that is safe and tolerableTo assess the efficacy of the combination of OPN-2853 and ruxolitinib for reduction in spleen size PROMise is a single country (UK) multicentre study, recruiting up to 60 patients with high or intermediate-2 risk MF who are not receiving an adequate response on ruxolitinib alone. Patients must have been treated with ruxolitinib for at least 24 weeks, on a stable dose for at least 4 weeks, and have ongoing splenomegaly. PROMise is split into three ruxolitinib dose categories based on platelet count which are assessed independently, Low Dose (5mg-20mg daily), Mid Dose (25mg-45mg daily) and High Dose (≥50mg daily). These are evaluated in combination with three OPN-2853 dose levels, Level 1 (20mg OD Decreased Dose), Level 2 (40mg OD Starting Dose) and Level 3 (80mg OD Increased Dose). Cohorts of patients (n=2-4) receive up to eight 21-day cycles of OPN-2853 and ruxolitinib. Patients are closely monitored for Dose Limiting Toxicities in cycle 1. The Trial Safety Committee (TSC) meets following cycle 1 to establish the dose recommendations of OPN-2853 for each dose category using the continual reassessment method (CRM). The CRM is utilised independently for each dose category, as such it is possible for the low, mid and high doses to be allocated to different OPN-2853 doses. Following cycle 8, patients may continue to receive OPN-2853 if experiencing clinical benefit and are followed up annually. Peripheral blood, bone marrow aspirate and bone marrow trephine samples are taken from all patients to measure the proportion who achieve a molecular response, and to determine the on target transcriptional response in myeloid cells. Additionally, pharmacokinetic samples are taken at specified timepoints pre and post dose to establish PK properties of OPN-2853 in combination with ruxolitinib. Current Status: To date PROMise has recruited 14 patients across all dose categories, and two TSC meetings have taken place.

Performance and Interlaboratory Reproducibility of Droplet Digital Polymerase Chain Reaction (ddPCR) and Real Time PCR for KIT D816V Mutation Detection: A Nationwide Pilot Study By the RIMA (Rete Italiana Mastocitosi) Association

Systemic Mastocytosis (SM) is a rare hematological neoplasm, but its incidence is probably underestimated because of the heterogeneity of clinical symptoms and presentation that may cause diagnostic difficulties especially outside reference centers. Detection of the activating D816V KIT mutation in the bone marrow or peripheral blood is one of the minor criteria for the diagnosis of SM, but it poses some challenges since in the indolent forms (the most frequent) the mast cell burden is very low. For this reason, the National Comprehensive Cancer Network and the European Competence Network on Mastocytosis (ECNM) recommend a high-sensitivity PCR-based assay, such as Allele-Specific Oligonucleotide-Real Time Quantitative PCR (ASO-qPCR) or ddPCR, while Sanger and Next Generation Sequencing are considered not adequate. Accurate quantitation of allele burden (AB) is also desirable since it offers diagnostic (an AB³10% qualifies as a B-finding according to the latest WHO classification) and prognostic information and might be used to monitor response to tyrosine kinase inhibitors. Despite the widespread routine availability of real time and digital PCR technologies, a map of labs across Italy offering KIT D816V testing with adequate sensitivity is lacking, nor have cooperative efforts aimed to check lab performance and reproducibility of diagnostic results ever been performed. Based on these premises, RIMA undertook, with the sponsorship of the GIMEMA Working Party on Chronic Myeloproliferative Neoplasms, a project aimed to: i) build a nationwide network of competent reference laboratories performing KIT D816V mutation testing; ii) promote harmonization of local procedures and ensure adequate proficiency and cross-comparability of results. The pilot phase of this project involved 7 labs (L) spread across the country (Milan, Bologna, Verona, Florence, Rome, Naples, Pavia) serving one or more reference clinical centers for the diagnosis and management of SM. First, a survey aimed to assess the techniques and procedures in use in each participating lab was conducted. Five labs (L2-L6) used a commercial ddPCR assay (KIT p.D816V c.2447A&amp;gt;T, Assay ID dHsaCP2000023; Bio-Rad); one lab (L7) used a home brew ASO-qPCR assay; one lab (L1) used a commercial semi-quantitative real time PCR-based assay (PlentiPlex Mastocytosis D816V kit; Pentabase). All labs performed analyses in duplicate or triplicate using DNA as input material, with amounts variable from 50 to 250ng/replicate. Reported limit of detection (LoD) was 0.0003% for the home brew method and 0.01% for the commercial methods. Subsequently, a round robin test to evaluate and compare performance in terms of sensitivity and inter-lab reproducibility was carried out. Mutated and wild-type DNA isolated from HMC-1.2 and HL-60 cells, respectively, was mixed and diluted to mimic different D816V ABs, from 10% down to 0.01%. Dilutions were externally assessed by the UK Wessex Genomics Laboratory Service, using an accredited ddPCR assay with a limit of detection (LoD) of 0.01%. Of note, the sixth dilution (D6) was scored as slightly below their LoD (0.008%; 3 positive droplets only). Identical batches of blinded vials were then distributed and analyzed in parallel by the 7 participating labs according to their own routine protocols. Positivity/negativity as scored by L1-7 and AB values as scored by L2-7 are detailed in Table 1. All the evaluated methods proved highly accurate in the detection and, for ddPCR and ASO-qPCR, in the quantitation of the KIT D816V (R 2 between 0.988 and 0.998). A very high degree of concordance was achieved, for all dilutions, across different labs and methods (CV between 0.07 and 0.8). D6 was scored borderline by L1 and positive by all other labs. This pilot experience demonstrates that the evaluated PCR-based methods may reliably identify and quantitate the KIT D816V mutation down to an AB of 0.01% with a high degree of cross-comparability of results, thus assisting clinicians in the diagnosis and monitoring of SM patients. To the best of our knowledge, this is the first cooperative effort aimed to assess the performance and reproducibility of KIT D816V mutation testing in SM. Involvement of additional Italian labs is already planned, and further implementation within the ECNM will be proposed. Definition of common SOPs, uniform sample requirements and web-based reporting following the GIMEMA LabNet model will be pursued.

Genetic Evolution from Chronic Myeloproliferative Neoplasms to Acute Myeloid Leukemia: An Analysis of Forty-Six Paired Samples

Background: Secondary acute myeloid leukemia (sAML) may arise from chronic myeloproliferative neoplasm (MPN). The genetic evolution pattern may be understood by paired sample analysis. Knowledge of genetic change in MPN/sAML is still limited and more extensive studies should be done. Patients and Methods: Forty-six paired samples (27 males) at diagnosis of MPN (12 polycythemia vera, 6 essential thrombocythemia, 25 primary myelofibrosis and 3 MPN-unclassified) and sAML transformation were available. Mutational analyses of 27 genes ( JAK2V617F, CALR, MPL, ASXL1, IDH1, IDH2, TET2, DNMT3A, EZH2, SRSF2, U2AF1, SF3B1, ZRSR2, SMC1, STAG2, SMC3, RUNX1, SETBP1, IKZF1, WT1, K-RAS, N-RAS, C-CBL, TP53, RAD21, BCOR and BCORL1) were performed. Mutations and their variant allele frequencies (VAF) were measured by next generation sequencing. Results: At baseline (MPN), the mutation number was 2 (maximal 5). Forty-five samples harbored driver gene mutations (31 JAK2V617F, 13 CALR and 1 MPL). Twenty-eight samples harbored at least one epigenetic regulator mutations (11 TET2, 8 DNMT3A,7 ASXL1, 5 EZH2, 2 IDH2, 1 IDH1). Twelve samples harbored spliceosome mutations which were mutually exclusive (6 SRSF2, 3 SF3B1, 2 U2AF1 1 ZRSR2). Other mutations were RUNX1, BCORL1 (n=2 each), CBL and BCOR (n=1 each). In sAML, the median mutation number was 3 (maximal 7). Loss of mutation was found for JAK2V617F (9/31), TET2 (1/11) and SRSF2 (1/6). Acquisition was most common for RUNX1 (n=9), followed by TP53, ASXL1 (n=5 each), K-RAS (n=4) , ZRSR2, STAG2 (n=3 each). The median number of acquired mutation was 1 (maximal 5). The frequencies of gene mutations are summarized in Figure 1A. The baseline VAF of JAK2V617F was high (&amp;gt;35%) in 80.6% (25/31). In progression to sAML, VAF was constant in 29.0% (9/31, VAF changes &amp;lt;10%), increased in 20.0% (9/31, increased VAF&amp;gt; 10%), decreased in 41.9% (13/31, decreased VAF&amp;gt;10%) (Figure 1B). The baseline VAF in CALR mutation was high (&amp;gt;35%) in 91.3% (12/13). VAF remained stable in 76.9% (10/13), and loss of CALR mutation was not observed (Figure 1B). TET2 mutations tended to be stable (7/16), but clonal expansion (5/16 of all mutation events at MPN), or acquisition (n=2) could be found during transformation to sAML. DNMT3A mutations remained stable (5/8), exhibited clonal expansion (2/8), or acquisition (n=1) in sAML progression. ASXL1 mutations remained stable (6/7), with clonal expansion (1/7), or acquisition (n=5) during MPN/sAML progression. All EZH2 mutants had clonal expansion (5/5) and one acquired in sAML (Figure 1B). We found that CALR mutationwas often the founding clone with high VAF at MPN phase, stable clone during sAML, and might acquire mutations in signaling pathways (1 CBL, 1 KRAS), epigenetic regulators (2 ASXL1, 1 IDH2), transcription factors (2 RUNX1, 1 BCOR), spliceosome (2 ZRSR2, 1 SF3B1), and cohesin complex (1 STAG2). JAK2 mutationwas often preceded by other ancestral mutations such as TET2, ASXL1, DNMT3A, EZH2, IDH2, SRSF2 or ZRSR2. During evolution, leukemia arose from non- JAK2 mutated clones with mutations in EZH2, DNMT3A, RUNX1, EZH2, SETBP1, or acquisition of TP53, SF3B1, BCOR and STAG2 mutations) in sAML. In outcome, the median time from MPN to sAML was 82 (range 3.7 to 338.5) months. Female gender, loss of JAK2V617F, presence of U2AF1 and absence of IDH1 were associated with shorter time to sAML transformation. No other genetic mutation in our gene panel or the number of mutations harbored by patients in our cohort had significant impact on time to sAML. Marked increase of VAF was observed for JAK2 (7/22) , DNMT3A (1/7) , IDH1 (2/3), IDH2 (1/3), TET2 (3/10) , EZH2 (4/5), C-CBL (1/1) and SRSF2 (1/4). Marked decrease of VAF was observed for JAK2 (4/22), MPL (1/1), DNMT3A (1/7) , ASXL1 (1/8), SF3B1 (2/3), SRSF2 (1/4) and U2AF1 (1/2). Multiple mutational clones were detected for TET2 (two clones in 4 samples and 3 clones in 1). Clonal expansion and reduction were observed in two pairs of samples upon sAML transformation. Conclusions: At the MPN stage, most patients had driver mutations with frequent co-mutations of epigenetic modifier or spliceosome genes. CALR mutant clones were stable while for JAK2, sAML often arose from clones without JAK2V617F which acquired RUNX1, TP53, ASXL1 and K-RAS. Research funding:Ministryof Science and Technology Council,Taiwan (NSTC 112-2314-B-182-055) and Ministry of Health and Welfare, Taiwan (112-TDU-B-222-124001)