Diagnosis Of Polycythemia Vera Research Articles

Histopathological Confirmed Polycythemia Vera with Transformation to Myelofibrosis Depicted on [18F]FDG PET/CT.

We present a case of a 59-year-old male diagnosed with polycythemia vera (PV) for many years, who presented with a relatively abrupt onset of heavy constitutional symptoms, including fatigue, night sweats, and a 10% weight loss over 6 weeks. Despite the known initial diagnosis of PV, the presence of profound B-symptoms prompted further investigation. A positron emission tomography/computed tomography (PET/CT) scan with 18F-Fluorodeoxyglucose ([18F]FDG) was performed to exclude malignant diseases. The [18F]FDG PET/CT revealed intense metabolic activity in the bone marrow of the proximal extremities and trunk skeleton, as well as a massively enlarged spleen with increased metabolic activity. Histopathologically, a transformation to myelofibrosis was revealed on a bone marrow biopsy. The case intends to serve as an exemplification for [18F]FDG PET/CT in PV with transformation to myelofibrosis (post-PV myelofibrosis).

The Systemic Inflammation Index: A New Candidate Minor Criterion in the Diagnosis of Polycythemia Vera.

To investigate inflammation indices and erythropoietin levels for their potential role in distinguishing polycythemia vera from secondary polycythemia and to compare different parameter combinations in terms of the diagnostic accuracy. This retrospective cohort was created from patients assessed for polycythemia from January 2020 to December 2023. Polycythemia vera diagnosis was made according to the 2016 World Health Organization criteria (n = 145). Those who did not fulfill the criteria were defined as having secondary polycythemia (n = 84). The neutrophil lymphocyte ratio, platelet lymphocyte ratio and systemic immune-inflammation index were significantly higher in the polycythemia vera group (p < 0.001 for all). Erythropoietin had the highest area under the curve in the analysis to distinguish groups, followed by the systemic immune-inflammation index. The platelet lymphocyte ratio (≥135) had the highest specificity to detect polycythemia vera, followed closely by the systemic immune-inflammation index. The sensitivity for polycythemia vera detection was highest with the erythropoietin and systemic immune-inflammation index combination, followed by erythropoietin and the neutrophil lymphocyte ratio. All the single and combinatory variables exhibited significant performance in predicting polycythemia vera after adjusting for age and sex. However, the erythropoietin and systemic immune-inflammation index combination had the highest odds ratio, followed by erythropoietin alone. These are promising findings supporting the usability of these biomarkers, especially the systemic immune-inflammation index, as minor criteria in the diagnosis of polycythemia vera. It is especially crucial to note that using erythropoietin in combination with these markers may improve diagnostic accuracy.

Polistemi Vera ve Esansiyel Trombositemi Tanısı Alan Hastalarda Elektrokardiyografik ve Ekokardiyografik Bulgularının Değerlendirilmesi

Background/Aims: Polycythemia vera (PV) and essential thrombocythemia (ET) are chronic myeloproliferative diseases. Along with the increase in myeloproliferative cell lines, they can cause various clinical outcomes such as arterial and venous thrombosis, pulmonary hypertension, and myocardial infarction. This study was designed to evaluate the cardiac effects of these diseases via electrocardiography and echocardiography. Methods: A total of 50 patients with a diagnosis of PV, 50 patients with a diagnosis of ET, and 50 healthy individuals as a control group were included in this study. Data on patient demographics were recorded in all subjects. All patients and control subjects had electrocardiography (ECG) recordings and routine transthoracic echocardiographic examination. Pulse wave velocity (PWV) was assessed with a Holter blood pressure device. Results: In total, 50 PV patients, 50 ET patients, and 50 control group were included in the study. The demographic characteristics of the PV, ET and control groups were similar. The PR interval was significantly shorter in control subjects than in PV and ET patients (p:0.007, p:0.024). Although the measured values were within normal limits, diastolic posterior wall thickness was significantly lower in the control group compared to PV and ET patients (p:0.019, p:0.009). PWV was significantly higher in ET patients compared to the control group (p:0.012). Conclusion: In this study, evaluating the effects of PV and ET on electrocardiography and transthoracic echocardiography; ECG parameters used to predict ventricular arrhythmias (QT, QTc, Tp-Te, Tp-Te/QT) and Pulmonary Artery Pressure showed no significant change, in opposition to existing literature. Nonetheless, similar to previous publications, PV and ET were found to negatively affect the diastolic function parameters on transthoracic echocardiography. While the aortic stiffness was significantly higher in ET patients compared to the control group, no significant difference was noted between PV patients and control subjects in terms of aortic stiffness.

A Real-World Evaluation of Risk Factors for Disease Progression in Patients with Polycythemia Vera (PV) Enrolled in REVEAL

Background: PV is a myeloproliferative neoplasm complicated by symptom burden, splenomegaly, vascular events, and disease progression to myelofibrosis (MF). Current risk models for PV include advanced age and history of thrombotic events (TEs), yet information on risk factors for PV progression is limited. In this analysis, we assessed the rate of PV progression to MF during the P rospective Obs ervational Study of Patients With Polycythemia Vera in US Clinic al Practices Trial (REVEAL) and assessed baseline demographics and disease characteristics as risk factors for PV progression. Methods: Criteria for enrollment in REVEAL included a physician-reported PV diagnosis. PV progression was defined by meeting any of the following criteria during the study: 1) Death from MF/myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML); 2) new/worsening splenomegaly, plus 2 of the following criteria: white blood cell (WBC) count &amp;gt;11×10 9/L, platelets (PLT) &amp;lt;100×10 9/L, hemoglobin (Hb) &amp;lt;10 g/dL; 3) evidence of progression to MF from bone marrow (BM) biopsy; 4) new/worsening splenomegaly, plus blasts &amp;gt;1%. Univariate and multivariate logistic regressions were performed to assess risk factors of PV progression. Results: Of the 2510 patients enrolled in REVEAL, 1191 (47.5%) were reported to have a JAK2 mutation at enrollment. To confirm PV diagnosis, digital droplet PCR for JAK2 p.V617F was performed on all patients with the first available biospecimen from an optional biological specimen substudy; 1520/1871 (81.2%) were positive. A further 367 patients with a physician-reported JAK2 mutation and 135 with a PV diagnosis confirmed by BM aspirate/biopsy were included; 488 patients (19.4%) who did not meet any criteria were excluded. Of the 2022 patients with confirmed diagnosis, median (range) follow-up was 44.1 (0-59.5) months; 134 (6.6%) progressed to MF (BM evidence of MF, n=69 [3.4%]; new/worsening splenomegaly, plus 2 of the following criteria WBC count &amp;gt;11×10 9/L, PLT &amp;lt;100×10 9/L, Hb &amp;lt;10 g/dL, n=44 [2.2%]; new/worsening splenomegaly, plus blasts &amp;gt;1%, n=37 [1.8%]; death from MF/MDS/AML, n=22 [1.1%]). A nonsignificant trend toward higher mean JAK2 p.V617F variant allele frequency was observed in patients with vs without progression (Table 1). Compared with patients without progression to MF, patients with progression were of similar age (69.5 vs 68.0 y) and had a longer time from PV diagnosis to enrollment (median, 7.2 vs 3.7 y; P&amp;lt;0.0001; Table 1). The percentage of patients with vs without progression enrolled via academic practices was 23.1% vs 16.9%; the percentage of patients with vs without progression who had no cytoreductive treatment prior to enrollment was 85.1% vs 91.2%. PV risk stratification (age &amp;gt;60 y or history of TEs) at enrollment was similar for patients with vs without progression (high risk, 61.9% vs 63.5%). However, a higher percentage of patients with vs without progression had a history of TEs at enrollment (29.9% vs 19.7%; P=0.0050). Univariate analysis also identified hematocrit (HCT) ≤0.45 L/L (63.9% vs 53.5%; P=0.0288) and WBC count &amp;gt;11×10 9/L (50.4% vs 31.8%; P&amp;lt;0.0001) at enrollment as significantly different between patients with vs without progression, respectively (Figure 1). In univariate analyses, time from PV diagnosis, TE history, HCT ≤0.45 L/L, WBC count &amp;gt;11×10 9/L at enrollment were each associated with increased PV progression risk (Figure 1). These factors were retained as significant covariates in multivariate analyses with stepwise model selection (OR [90% CI]: time from PV diagnosis to enrollment, 1.030 [1.016-1.044], P&amp;lt;0.0001; history of TEs at enrollment, 1.96 [1.281-2.998], P=0.0019; HCT &amp;gt;0.45 vs ≤0.45 L/L, 0.637 [0.421-0.964], P=0.0330; WBC &amp;gt;11 vs ≤11×10 9/L, 2.205 [1.477-3.292], P&amp;lt;0.0001). Conclusions: This real-world analysis of prospective data from REVEAL found that 6.6% of patients with PV progressed to MF over the median 44.1 months of follow-up. Time from diagnosis to enrollment and history of TEs were each significantly associated with an increased risk of PV progression; the latter finding regarding TE history was unexpected and represents a potentially novel risk factor for PV progression. HCT ≤0.45 L/L and WBC &amp;gt;11×10 9/L at enrollment were also significantly associated with an increased progression risk. Additional analysis is ongoing to better understand the causal relationships between these risk factors and PV progression.

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.

Prospective Symptom Burden Analysis in 784 Patients with Myeloproliferative Neoplasms: High Burden Correlates with Inflammatory/Genetic Biomarkers and Reduced Survival

Background: Myeloproliferative neoplasms (MPN) are associated with significant symptom burden, influencing patient quality of life and management. Thorough assessment of this burden is crucial; however, data from large populational registries are limited. Our objective was to characterize symptom burden in a large MPN cohort, determining: i) age-associated differences; ii) treatment effect; iii) biologic correlatives, and iv) impact on overall survival (OS) in a large, real-world population based setting. Methods: This is a multicenter prospective study analyzing patient-reported outcomes per MPN-Symptom Assessment Form Total Symptom Score (MPN-SAF TSS), a validated questionnaire grading (0-10) ten MPN symptoms ( JCO, 2012). Recruitment: Quebec CML-MPN Research Group registry (&amp;gt;20 community/academic centers). Eligibility: i) diagnosis of polycythemia vera (PV), essential thrombocytosis (ET), or myelofibrosis (MF) per WHO criteria; ii) completion of 1+ MPN-SAF TSS between 2013-2022. Conventional statistics were used (JMP® Pro 14.1.0 software; SAS Institute, NC, USA). Results: 4105 MPN-SAF TSS were completed by 784 patients (n= 285 PV, n=422 ET, n=77 MF). Median age at diagnosis was 63 years (range 19-96); female preponderance (56%). A median of 5 questionnaires were completed/patient (range 1-16). Mean symptom score was 16.7 (+/-12.3). A clinically significant total score, defined as &amp;gt;20, was reported by 33% of patients (n=261); most frequently women (p&amp;lt;0.0001) and MF cases (p=0.03). Symptom burden in the young: N=74 (9%) were age &amp;lt;40 years at diagnosis. At recruitment, mean aggregate and maximum MPN-SAF TSS scores were comparable across younger and older subsets (p=0.3-0.9) (Table 1), despite lower risk scores in the former (p&amp;lt;0.05). When scores were deconstructed, younger patients - vs older, had significantly higher levels of fatigue (p=0.03) and abdominal pain (0.007). Impact of therapy: Of those with high MPN-SAF scores, a considerable proportion were not treated (n=69/179, 39%). Higher mean scores were also reported in those having initiated therapy &amp;gt;36 months from diagnosis (p=0.0009). Of those with available MPN-SAF pre/post treatment, 37% showed deteriorating scores following cytoreduction, regardless of agent (p=0.4). Notably, those not on antiplatelet therapy had significantly higher mean (p=0.0006) and sub-item scores (excluding fever/night sweats). Over time, all interventions confounded, n=338 (43%) experienced worsening of MPN-SAF scores. Clinical biomarkers: Patients with anemia (hemoglobin &amp;lt;100 g/L) had significantly higher mean MPN-SAF scores and worse fatigue, inactivity, concentration, bone pain, and weight loss (all p&amp;lt;0.05). Increased C reactive protein (CRP) associated significantly with higher MPN-SAF scores (p=0.03), as well as fatigue, inactivity, early satiety, and bone pain (all p&amp;lt;0.05). Notably, patients with JAK2V617F variant allele frequency &amp;gt;50% (VAF) had higher average (p=0.03) and maximum (p=0.001) MPN-SAF, higher inactivity scores (p=0.02), and more frequent worsening scores over time (p=0.05). Survival impact: Higher mean MPN-SAF score had a significantly detrimental impact on OS (p=0.05) (Figure 1). Multivariate analysis revealed absence of antiplatelet therapy, age at diagnosis &amp;gt;65 years, male sex, and high-level inactivity to be independent predictors of inferior OS (HR 29, 6, 3 and 3 respectively). Conclusions: This is a large-scale study comprehensively appraising symptom burden in MPN patients, disclosing several novel findings. First, it unexpectedly exposes disproportionately severe symptoms (fatigue/abdominal pain) in younger patients. Second, it reveals deterioration of symptoms in the face of therapy in a significant number of patients, underscoring inadequacy of current therapies in symptom control. Third, it discloses anemia, elevated CRP, and JAK2 VAF&amp;gt;50% as putative biomarkers of symptom burden; potential adjuncts in identifying highly symptomatic subsets, particularly in situations where symptom assessment is challenging. Finally, it confirms negative survival impact of high symptom burden in a real-world setting. Overall this data exposes a critical unmet need for new therapeutic avenues aimed at alleviating symptom burden in patients with MPN. Further delineation of the inflammation-symptom relationship and future studies using novel prevention strategies are warranted.

Real World, Single-Centre Experience of Pregnancy in Patients with Philadelphia Negative Myeloproliferative Neoplasms

Pregnancy in myeloproliferative neoplasms (MPN) is commonly associated with maternal and foetal complications due to increased risks of thromboembolic and haemorrhagic events and placental dysfunction. The incidence of UK pregnancies in MPN is estimated as 3·2/100 000 maternities per year (Alimam, S., et al 2016, Br J Haematol 2016; 175:31-36; Robinson et al, Br J Haematol 2020;189:625-34). Here we present pregnancy outcomes of MPN patients attending University College London Hospital (UCLH), a large UK tertiary referral centre, between 2015 and 2023. Twenty-three patients were identified with a median age at MPN diagnosis of 33 years (range (r), 13 - 46). The majority of patients (21/23, 91.3%) had a diagnosis of ET or triple negative (TN) thrombocytosis and 8.7% (2/23) a diagnosis of polycythaemia vera (PV). In 61.4% of pregnancies, diagnosis was known at conception. Regarding mutational status, JAK2V617F was present in 10/23 (43.5%) patients, CALR in 5/23 (21.7%) and MPL in 1/23 (4.3%). The remaining 7/23 (30.4%) patients were TN. Median VAF for JAK2V617F and CALR were 15.8% (r, 21.1 - 33%) and 25.9% (r, 5.7 - 46%), respectively. The cohort collectively experienced 57 pregnancies, 38 of which were managed at UCLH. Focusing on pregnancies managed at UCLH, median age at pregnancy was 34.5 years (r, 22 - 47). Conception was spontaneous in 31/38 (81.6%) pregnancies. Six (15.8%) patients required assisted conception and had a higher median age of 38.5 years (r, 35 - 47). Where gestation at delivery was known, 92.6% (25/31) of live births delivered at term (&amp;gt;37 weeks). Caesarean rate was significant at 41.9% (13/31), of which 61.5% were emergency sections. The live birth rate of the 57 overall pregnancies was 76.9% and 88.6% in the 38 managed at UCLH. At UCLH, we adopt an individualised approach to managing pregnant women with MPNs, working alongside obstetricians and obstetric haematology colleagues. Consequently, as shown in Table 1, there were bespoke regimens for individual patients. Low dose aspirin was prescribed throughout pregnancy in the majority (78.9%, 30/38) of pregnancies. In 18.4% (7/38), cytoreduction was established prior to pregnancy. In 42.9% (3/7), pegylated interferon (PegIFN) was commenced to optimise counts prior to pregnancy and in 42.9% (3/7) as long term count control. One patient was cytoreduced with hydroxycarbamide prior to pregnancy and subsequently switched to PegIFN. Low molecular weight heparin (LMWH) was administered at some point during pregnancy in 60.9% (14/23) of patients and 57.9% (22/38) of pregnancies. 65.8% (25/38) underwent monitoring with uterine artery (UA) dopplers. Median gestation for UA assessment was 20 weeks (r, 19 - 28). UA dopplers were reported as abnormal in 16% (4/25). In two patients, this was due to a raised combined pulsatility index, UA notching in one and was unspecified in one patient. Nine (39.1%) patients experienced foetal loss, with 12 miscarriages recorded across the total 57 pregnancies and 4 miscarriages in the 38 pregnancies managed at UCLH. Median maternal age was 31.5 (r, 24 - 42) and median gestation was 8 weeks (r, 5 - 24). Six (66.7%) patients experiencing foetal loss had a diagnosis of ET, 2 (22.2%) PV and 1 (11.1%) TN thrombocytosis. Three miscarriages occurred in one patient, who demonstrated a concurrent heterozygous prothrombin G20210A mutation in addition to ET. Eight (34.8%, 8/23) patients collectively experienced 11 haemorrhagic events. The majority (72.7%) were post-partum haemorrhage (PPH), 37.5% of which were classified as major or severe. Three (27.3%) bleeding events occurred whilst on aspirin monotherapy, 3 (27.3%) on combined LMWH and aspirin, 1 (9.1%) on LWMH alone and 1 (9.1%) on LMWH and PIFN. With regards to thrombosis, one patient with undiagnosed ET had a cerebral venous sinus thrombosis at 11-weeks gestation. A total of 2/23 (8.7%) patients' pregnancies resulted in hypertensive complications and pre-eclampsia, both resulting in delivery with caesarean section at 34 and 35 weeks. Although the live birth rate is encouraging, our data highlights that patients with MPN remain at increased risk of miscarriage, early delivery and haemorrhagic events. There remain inconsistencies in the management of pregnancy in MPN and, although we adopt an individualised patient-centred approach, there is an unmet need for further study and development of evidence based treatment algorithms.

The Utility of a Coagulation Laboratory Profile in Addition to Clinical Risk Factors for Thrombosis Risk Evaluation in Patients with Myeloproliferative Neoplasms: A Pilot Study

Background: Patients (pts) with myeloproliferative neoplasms (MPN) have a significantly increased risk of arterial and venous thrombotic events (TEs), while some pts may paradoxically suffer from bleeding manifestations. Thrombosis risk evaluation in polycythemia vera (PV) and essential thrombocythemia (ET) has important implications for patient management, however, the currently used risk stratification models are extremely limited. Methods: We designed a pilot study to assess the utility of an expanded coagulation laboratory profile in addition to other clinical variables for thrombosis and bleeding risk evaluation in a heterogenous MPN patient population. Our laboratory profile included PT, aPTT, fibrinogen, D-dimer, von-Willebrand Factor (vWF) antigen and activity testing, platelet (PLT) aggregation studies and thrombin generation assay (TGA, ST-Genesia, Stago, France), along with CBC and comprehensive biochemistry studies. Blood was drawn from pts visiting the hematology clinics or day care at Hadassah Medical Center. Clinical and demographic data were collected retrospectively from electronic medical records. The study was approved by the local IRB committee. Results:74 pts were included in the study; the mean age was 59.7 years and 51% were women. Sixty percent had a diagnosis of PV, 20% had ET, 17.6% had myelofibrosis (MF) and 2.7% had MPN unclassifiable. 78% of the pts harbored a JAK2V617F mutation, 8% and 2.7% harbored CALR and MPL mutations, respectively, and 11% were negative to all three MPN driver mutations. 63% of the pts had at least one cardiovascular risk factor, most commonly hypertension (HTN) and dyslipidemia. Most of the pts were treated with antiplatelet agents (62%), anticoagulants (16%) and/or cytoreductive agents (58%). Of 74 pts, 31% had a history of TEs (20% arterial, 11% venous), 22% reported suffering from microvascular symptoms, and 20% had experienced bleeding. The high rate of bleeding manifestations in our study population suggests an underestimation of the bleeding burden in MPN, as proposed by our group previously [Rottenstreich, Eur J Intern Med 2017]. Other patient characteristics were overall comparable to MPN patient populations in other studies (Table 1). In multivariate analyses, history of TEs was significantly associated with older age, type 2 diabetes mellitus (DM2), HTN and dyslipidemia, but not with gender, MPN subtype, driver mutation status or smoking. Pts with history of TEs had significantly lower hematocrit and prolonged PT/INR, associated with a higher rate of treatment with cytoreduction and anticoagulation, respectively, in these pts. Interestingly, pts with TEs had significantly higher vWF antigen levels (p=0.007), which were independent of age, blood counts and treatments, a finding not previously reported in MPN. No association was observed between TEs and PLT or WBC counts, D-dimer levels and vWF activity (Table 2), however, vWF activity was decreased in pts with higher PLT counts. TGA was of key interest in this study. In 62 pts not receiving anticoagulation, we observed an association between prolonged lag time (suggesting decreased coagulability) and older age, male gender and (near significant trend) JAK2V617 negative status, but did not find a correlation to TEs, blood counts and other variables. PLT aggregation indices were not associated with TEs, bleeding history or blood counts. In multivariate logistic regression analyses, history of DM2 and HTN, and vWF antigen levels, showed the strongest association to TEs, which was independent of age, blood counts and all other variables. A risk-model incorporating these variables showed a sensitivity of 77% and specificity of 92% for history of TEs in our study population. Conclusions: Despite being limited by a small and heterogenous study population and retrospective data collection; these findings support the utility of a coagulation laboratory profile in the evaluation of thrombosis and bleeding risk in MPN. The potential of TGA in risk evaluation in MPN is intriguing but merits further research. The multivariate risk-model incorporating history of DM2 and HTN along with vWF antigen levels merits validation in larger studies. Based on this pilot, a prospective study following over 250 pts with PV and ET (excluding overt MF) was initiated. This study will include NGS mutational profiling and JAK2V617F allele burden testing and omit the use of PLT aggregation studies.

Durability of Hematocrit Control in Polycythemia Vera with the First-in-Class Hepcidin Mimetic Rusfertide: Two-Year Follow up Results from the Revive Study

Background: Polycythemia vera (PV) is a myeloproliferative neoplasm associated with uncontrolled erythrocytosis, systemic symptoms, and an increased risk of thromboembolic and cardiovascular complications largely driven by uncontrolled hematocrit (HCT) levels. Rusfertide is a hepcidin mimetic that controls red blood cell production in PV patients by limiting iron availability. The REVIVE trial (PTG-300-04; NCT04057040) is investigating rusfertide and consists of three stages. Eligibility criteria: diagnosis of PV; ≥3 therapeutic phlebotomies (TP)s in the 28 weeks prior to enrollment with or without concurrent cytoreductive therapies (CYTO). As reported previously, adding rusfertide to standard of care PV treatments optimally controls HCT levels and decreases the need for TP (Kuykendall et al., HemaSphere, 2022;6:(S3):1766; Kremyanskaya et al. EHA2023; Abstract LB2710). Herein, we report results from the ongoing open-label extension (OLE) from REVIVE (Part 3) and explore the long-term durability of response to rusfertide. Methods: During Part 1 (Week 1-29), treatment with rusfertide was initiated at 20 mg and individually titrated to control hematocrit (&amp;lt;45%); the median was 40 mg/wk and relatively stable after achieving a therapeutic dose. In Part 2 (Week 29-41), the blinded randomized withdrawal phase, patients were randomized to either continue rusfertide or to matching placebo. Any randomized patient who responded or did not respond was allowed to participate in Part 3 (3-yr OLE). The investigators can adjust doses of rusfertide and CYTO as needed to manage PV symptoms and blood counts. During Part 3, the hematocrit, erythrocytes, leukocytes, platelets, and ferritin are being assessed to determine long-term durability of response to rusfertide. Results: In Part 1 of REVIVE, 70 patients were enrolled, 59 were randomized, and 58 continued into the OLE (Part 3). As of July 11, 2023, of the 70 enrolled patients, 57 (81.4%) patients have been treated for ≥1 year, 46 (65.7%) for ≥1.5 years, and 24 (34.3%) for ≥2 years. For subjects continuing in Part 3, the median age was 57 years (range, 27-77); 41 (70.7%) were men, and 17 (29.3%) were women. Thirty-two (55.2%) of the 58 subjects were treated with phlebotomy (PHL); 26 (44.8%) were receiving concurrent therapy with CYTO. All patients were essentially phlebotomy-free while on rusfertide treatment. Mean platelet counts increased initially on average within 4 weeks following initiation of rusfertide but subsequently stabilized at approximately 30% increase by week 9 (Figure 1); platelets didn't increase with the increase in rusfertide doses either. The increased platelet counts were not associated with any bleeding or thrombotic events. Leukocyte counts remained stable. Treatment with rusfertide resulted in the consistent maintenance of hematocrit below 45% and an overall decrease in erythrocyte counts (Figure 2). This effect was lost temporarily for patients randomized to placebo during Part 2 and returned after resuming rusfertide treatment. Prior to enrollment, iron-related parameters were consistent with systemic iron deficiency (mean [±SE] ferritin 18.7 [±4.3] µg/L). Rusfertide treatment resulted in an improvement of serum ferritin towards normal levels (mean [±SE] ferritin 148.6 [±18.6] µg/L at Cycle 15 during the OLE) (Figure 2). Rusfertide was generally well tolerated; 80% of treatment-emergent adverse events (TEAEs) were grade 1-2, 20% were grade 3, and none were grade 4 or 5. The most common TEAEs were injection site reactions (ISRs), which were localized and grade 1-2 in severity and decreased in incidence with continued treatment. Six (8.6%) TEAEs led to treatment discontinuation. Conclusions: The REVIVE OLE demonstrated that rusfertide can provide long-term control of HCT, without phlebotomy, in patients with PV receiving TP with or without CYTO. Ferritin improved with rusfertide dosing and other lineages, after an initial increase in platelet counts both platelets and leucocyte counts remained stable during rusfertide treatment. Rusfertide was added to the current standard of care and was generally well-tolerated; most TEAEs were grade 1 or 2.

Epidemiological Profile of Polycythemia Vera Patients Diagnosed during 2016-2020: An Ethnic Variation in Armenia

Background: Polycythemia Vera (PV), a rare myeloproliferative neoplasm, exhibits variations in disease characteristics across diverse ethnic populations. Epidemiological data on PV patients in low-middle-income countries, such as Armenia, is scarce. This study represents the first comprehensive retrospective analysis of PV patients diagnosed between 2016 and 2020 in Armenia. It aims to provide valuable insights into disease characteristics, including median survival, gender distribution, hemoglobin levels, JAK2V617F mutation status, and treatment patterns. Additionally, it explores gender disparities in PV patients in Armenia which is essential to tailor appropriate therapeutic strategies. While previous studies have reported a consistent male-to-female ratio of 2:1 across all ethnicities, this research highlights a contrasting male-to-female ratio in Armenia. Methods: This study included all patients with a diagnosis of PV in the Republic of Armenia from 2016 to 2020, which were registered through the registry of the Hematology Center after Prof. Yeolyan, which stands as the sole hematology center in Armenia. Medical records were reviewed retrospectively and analyzed. Gender distribution was meticulously examined in the context of ethnicity, allowing for a nuanced understanding of the male-to-female ratio variation. Furthermore, the study explored additional epidemiological data, including median survival, hemoglobin levels, JAK2V617F mutation status, and treatment patterns. Results: This analysis provides the first in-depth epidemiological insights into PV patients in Armenia. Surprisingly, our findings indicate that in Armenia, the male-to-female ratio deviates from the established norm, manifesting as a male-to-female ratio of 1.0/0.8 (55.1% males, 44.9% females). This ethnic variation in gender distribution prompts further investigation into the underlying genetic and environmental factors that may contribute to the occurrence of PV within the Armenian population. Additionally, the study revealed a mean survival of 79.457 months (95% CI: 76.718 - 82.196). The median hemoglobin level was 198 g/l. JAK2V617F mutation analysis was conducted in a portion of the cases, with 81.4% of patients not undergoing testing. Among the cases where JAK2V617F mutation analysis was performed, 81.8% tested positive for the mutation, while 18.2% yielded negative results. The majority (88.1%) of PV patients received Hydroxyurea as a therapeutic intervention. However, limitations such as the absence of JAK2V617F mutation analysis in a substantial portion (81.4%) of cases highlight the challenges faced in resource-limited settings like Armenia. The high cost of Ruxolitinib poses further barriers to access for the patient population. Conclusion: This pioneering epidemiologic study in Armenia offers valuable insights into PV's characteristics within this unique ethnic context. The observed difference in the male-to-female ratio in PV patients in Armenia merits further investigation. Unraveling the factors contributing to this ethnic variation could provide crucial insights into the pathogenesis of PV and may aid in optimizing diagnostic and therapeutic approaches for this rare hematologic disorder in Armenia. Limitations: This nationwide study exploring PV in Armenia encountered limitations due to unavailable data for 26 cases, including 5 deceased patients. The retrospective design, and limited genetic testing data may impact the study's generalizability and disease characterization. Longitudinal follow-up and potential unmeasured confounding factors further warrant consideration.

Increase of Arterial Stiffness in Patients with Polycythemia Vera

Introduction: Preventing thrombotic adverse events (TAEs) is crucial in Polycythemia Vera (PV), as it is the leading cause of death. A targeted approach is required to achieve this, aiming to lower hematocrit (HCT) blood levels and manage thrombocytosis through cytoreductive therapy and anti-platelet treatments. The reasons behind the higher incidence of TAEs in PV are partially known. A novel perspective considers that increased blood vessel content may result in a stiffer aorta, which is clinically measurable with the Pulse Wave Velocity (PWV). The stiffer aorta, a proxy of arterial aging, has been recognized as a significant independent contributor to TAEs. Objectives: This study aimed to investigate the impact of hematological parameters on arterial stiffness in PV patients Methods: Clinical and laboratory information was collected for each patient. Aorta PWV (PWV) was estimated using the SphygmoCor System (AtCor Medical Pty Ltd., Head Office, West Ryde, Australia). The patients were observed and measured twice with a minimum interval of six months between sessions. Results: We evaluated patients with a diagnosis of PV according to WHO 2016 classification, attending from November 2021 to March 2023, the Hematology Unit of the Businco Hospital in Cagliari, Italy. The study involved 26 patients aged 27 to 77 years old. Among them, 58% were female. The median follow-up between diagnosis and PWV evaluation was 7±3 years. The median Hemoglobin (Hb) level was 13.9±1.7 g/dl, with an HCT level of 44.1±4.6 %. Leucocytes and platelets at evaluation time were 9.1±4.2×10 3/μL and 395±227 ×10 3/μL, respectively. Fourteen (53.8%) patients reported a high-risk thrombotic score at diagnosis, and 65.3% had at least one comorbidity. Two (7.7%) patients had diabetes. Moreover, 15.4% showed dyslipidemia, while 38.5% had arterial hypertension. The median body mass index (BMI) was 24.8 ± 3.6 Kg/m2, and the median waist circumference was 94.4 ±13.4 cm. Characteristics of patients were resumed in Table 1. A significant correlation with a high level of PWV was found with age (r:0.54, p=0.004), systolic and diastolic blood pressure (r:0.55, p=0.004 and r:0.44, p=0.025 respectively), heart rate (r:0.47, p=0.02), Hb (r:0.50, p=0.009), and use of hydroxycarbamide (r:0.42, p=0.03). Even after adjusting for age, waist circumference, BMI, and hypertension, the hemoglobin level still significantly correlated with PWV (β0.64 ± 0.27, p&amp;lt;0.05). No associations were found with hematocrit levels (β0.09 ± 0.12, p=0.42). When comparing patients treated only with phlebotomy versus those treated with hydroxycarbamide, PWV was significantly higher (stiffer artery) in the second group (8.9 ± 1.8 vs 11.2 ± 3.2, p&amp;lt; 0.05, respectively). Still, the difference lost significance when accounting for age and blood pressure levels. Conclusion: In PV, Hb levels showed a significant positive correlation with arterial stiffness, indexed as PWV, regardless of PV-specific treatment. The stiffer artery may contribute to the higher TAEs in PV patients. Reducing Hb levels in PV patients also seems beneficial for arterial aging. Further studies are necessary to determine the possible role of PWV in defining and preventing thrombotic events.

Associations and Hospital Outcomes of Splanchnic Vein Thrombosis in Patients with Polycythemia Vera

Background: Thrombosis means the presence of a blood clot in a blood vessel. While thrombosis is a relatively common condition in deep veins of the limbs and the lungs, its incidence in splanchnic veins is at least 25 times lower compared to the former. Splanchnic Vein Thrombosis (SVT) involves portal, hepatic, splenic or mesenteric veins. Polycythemia Vera (PV) is one of the significant myeloproliferative neoplasms (MPN) that cause SVT. Objectives: This study examines the relationship between PV and SVT and its impact on hospital outcomes, explicitly focusing on mortality rates in affected patients. Methods: This retrospective cohort study uses the 2018 to 2020 National Inpatient Sample (NIS) database. Our inclusion criteria were for patients 18 years or older with Splanchnic Vein thrombosis and Polycythemia Vera diagnosis during hospitalization. We defined splanchnic vein thrombosis as patients with portal and hepatic vein thrombosis. We examined these patients' demographics and their relationship with hospital outcomes, such as length of hospital stay, cost of hospitalization and mortality. Using univariate and multivariate logistics regression models, we measured mortality as the primary outcome. Result: We identified 160,570 patients with SVT, among whom 1,120 (0.69%) had PV. PV patients were primarily female and white, with a mean age of 58.9. The PV cohort exhibited a lower mortality rate of 4.5% compared to the SVT from other etiology. Being black, increasing age, and increasing comorbidity indices were associated with increasing mortality. Though not statistically significant, there was a trend of decreasing mortality in both unadjusted and adjusted models for PV [0.68, 95% CI (0.26-1.05)] and [0.55, 95% CI (0.26-1.16)], likely underpowered by the rarity of diagnosis. Conclusion: Our study shows that the mortality of SVT from PV was 45% lower compared to other causes of SVT. PV did not pose an increased mortality risk compared to other etiologies, and it was not statistically significant. There is a need for further studies to understand better and ultimately help in management guidelines for SVT in PV compared to SVT due to other causes.

Quantification of JAK2 V167F in Patients with Myeloproliferative Neoplasms: Comparison of NGS and Digital PCR with Quantitative PCR

Introduction: JAK2 V617F is the most common mutation in the Philadelphia-negative myeloproliferative neoplasms (MPN), detected in 97% of polycythemia vera (PV), and approximately 55% of essential thrombocythemia (ET) and primary myelofibrosis (PMF) cases. According to the WHO, JAK2 V617F positivity is a major criteria for PV, ET or PMF diagnosis. But JAK2 V617F quantification at diagnosis could be useful since a high allelic frequency (or VAF) has been associated with increased symptom burden in PV, risk of thrombotic events in ET and progression in PMF. The current gold standard technique for JAK2 V617F quantification is allele-specific quantitative PCR (qPCR). However, digital PCR (dPCR) is increasingly being employed since it permits absolute quantification of JAK2 V617F without the need for a standard curve. QPCR vs. dPCR comparisons have shown high conformance between the two methods. Moreover, next-generation sequencing technologies (NGS) are increasingly used for MPN diagnosis. The aim of this study was to evaluate the concordance between dPCR and NGS for JAK2 V617F quantification at diagnosis. Methods: JAK2 V617F was quantified in the same sample of genomic DNA, extracted from total leukocytes from peripheral blood or bone marrow at diagnosis, by digital PCR (dPCR) and by NGS. The Absolute Q™ Liquid Biopsy dPCR Assay (JAK2 12600) was used in the QuantStudio™ Absolute Q™ Digital PCR System (Applied Biosystems) with 25 ng DNA. This assay quantifies the number of JAK2 WT-VIC and JAK2 V617F-FAM positive signals in 20000 partitions, determined as copies JAK2 V617F/µl input sample, and expressed as percentage VAF, with a limit of detection of 0.1%. NGS was performed with the MiSeq (Illumina) platform and the targeted 30-gene panel Myeloid Solution™ (SOPHiA GENETICS) using 200 ng DNA. VAF was determined as the number of variant reads divided by the number of total reads (reported as a percentage), with a limit of detection of 2.5%. Statistical analyses were performed using R-commander version 2.8. P-values &amp;lt;0.05 were considered statistically significant. Results: The quantification of JAK2 V617F was carried out in a total of 52 patient samples with both techniques. Of the 52 patients, 5 had a diagnosis of ET and 47 had PV. The average VAF of JAK2 V617F using dPCR was 14.1% and 48.2%, and 17.1% and 47.6% using NGS for ET patients and PV patients, respectively. The concordance of positivity for JAK2 V617F between the two methods was 100%. With dPCR, the average VAF of JAK2 V617F was 44.62% (range 2.7%-100%). With NGS, the average VAF of JAK2 V617F was 44.95% (range 2.5%-96.5%), with an average coverage/read depth &amp;gt;3500 reads. At diagnosis, there was no difference in the mean VAF of JAK2 V617F determined using dPCR vs. NGS (44.62 vs. 44.95, p=0.792, paired Student t-test). There was an excellent correlation between the VAF of JAK2 V617F determined using dPCR vs. NGS (Pearson correlation coefficient 0.944, p&amp;lt;0.001; Figure 1). Only 7 samples had a deviation &amp;gt;10% in the VAF quantification. These determinations are indicated in orange in the graph and listed in the table . The cause of 2/7 deviations might have been a limited DNA volume/concentration available for dPCR. The high concordance of variant quantification by dPCR andNGS was maintained for JAK2 V617F with low VAFs (≤20%, mean 12.0% vs. 11.8%, respectively; p=0.840) and high VAFs (≥80%, mean 90.6% vs. 89.9%, respectively; p=0.858). Conclusions: Overall, excellent correlation was observed between the VAF of JAK2 V617F obtained using dPCR and NGS, showing that NGS is a robust quantification method. However, 7 samples had a difference &amp;gt;10% VAF, with a deviation &amp;gt;25% in 3 cases. Standardization of molecular techniques for JAK2 V617F quantification is important if the VAF is to be monitored during MPN patient follow-up as a biomarker for disease evolution and for response to treatment, with VAF reductions shown for pegylated interferon and ruxolitinib. DPCR might be better suited for follow-up quantification due to its higher sensitivity and lower price, while NGS at diagnosis, apart from detecting and quantifying JAK2 V617F at baseline, has the advantage of providing information on other gene mutations with prognostic value.

Secondary Polycythemia Associated with COVID-19 Is Associated with Higher Mortality but Does Not Seem to Affect Thrombotic Risk

Introduction Reactive polycythemia (without presence of a chronic myeloproliferative neoplasm (MPN)) is commonly observed among patients with chronic pulmonary disease, whereas its significance in the context of COVID-19 is less well known. We aimed to investigate to what extent might polycythemia at the time of hospital admission affect outcomes of acutely ill COVID-19 patients. Methods We retrospectively evaluated a total of 5872 consecutive hospitalized COVID-19 patients treated in a tertiary referral center, UH Dubrava Zagreb, Croatia, in period 3/2020-6/2021. All patients were of white race and adults. All patients were tested positive for SARS-CoV-2 with either PCR or antigen test in the presence of compatible clinical symptoms. Patients with missing laboratory or clinical information or with prior or subsequently proven MPN were excluded from analysis. Hemoglobin threshold levels defined by the World health organization (WHO) criteria for diagnosis of anemia and the 2008 and 2016 WHO criteria for diagnosis of polycythemia vera (PV) were used to stratify patients into four subgroups (anemia, normal hemoglobin values, 2016 but not 2008 WHO polycythemia vera (PV), and 2008 WHO PV hemoglobin criteria fulfilling patients). Patients were evaluated in regard to baseline clinical characteristics, in hospital mortality, venous (VTE), arterial thrombosis and major bleeding. Due to non-normal distribution, numerical variables were presented as median and interquartile range (IQR). The Kruskal Wallis ANOVA, the chi squared test and the logistic regression were used. P values &amp;lt;0.05 were considered statistically significant. All analyses were performed using the MedCalc statistical software version 22.007 (MedCalc Software Ltd, Ostend, Belgium). Results A total of 5872 COVID-19 patients were analyzed. There were 2575 (43.9%) female and 3297 (56.1%) male patients. Median age was 72 years, median Charlson comorbidity index was 4 points. A total of 4166 (70.9%) patients presented with severe and 897 (15.3%) with critical intensity of COVID-19 symptoms. Median hemoglobin level at the time of admission was 128 g/L, IQR (114-141). A total of 3082 (52.5%) patients presented with normal hemoglobin levels, 2607 (44.4%) with anemia, 158 (2.7%) fulfilled 2016 but not 2008 WHO PV hemoglobin criteria and 25 (0.4%) fulfilled 2008 WHO PV hemoglobin criteria. Patients presenting with polycythemia in comparison to those with normal hemoglobin values were significantly older, were more likely to be of male sex, had higher Charlson comorbidity index, higher leukocytes, lower platelets, higher intensity of COVID-19 symptoms, required higher intensity of oxygen supplementation both at the admission and later during hospitalization (P&amp;lt;0.05 for all analyses). Figure 1 depicts the relationship of belonging to different hemoglobin categories with clinical outcomes. Patients presenting with anemia (OR 1.42, P&amp;lt;0.001), WHO 2016 grade (OR 1.63, P=0.003) and WHO 2008 grade polycythemia (OR 4.98, P&amp;lt;0.001) had increased risk of mortality in comparison to patients presenting with normal hemoglobin values. Anemia was associated with higher VTE (OR 1.34, P&amp;lt;0.006) and major bleeding risk (OR 2.27, P&amp;lt;0.001) in comparison to normal hemoglobin values, whereas no significant association of polycythemia with venous or arterial thrombotic or major bleeding risk was observed. Relationship of anemia, WHO 2016 and WHO 2008 grade polycythemia with increased mortality remained significant after adjusting analyses for age, sex, Charlson comorbidity index, COVID-19 severity and need for mechanical ventilation, all independently predicting inferior outcome (P&amp;lt;0.05 for all analyses). Conclusion Secondary polycythemia in non-MPN COVID-19 patients is associated with high mortality, increasing with higher degree of polycythemia, but does not seem to affect thrombotic or major bleeding risk in comparison to normal hemoglobin values. These observations might help in understanding risks associated with polycythemia and increased blood viscosity in the context of other respiratory diseases. These findings might also translate into the context of MPN and COVID-19, suggesting that blood cells other than erythrocytes might play a more important role regarding thrombotic risk. Future studies are warranted.

Assessing the Feasibility of Thromboprophylaxis with Apixaban in JAK2-Positive Myeloproliferative Neoplasm Patients: The Airport-MPN Trial

Introduction: Thrombosis is a major cause of mortality and morbidity in myeloproliferative neoplasms (MPN). In patients classified as high-risk for thrombosis, current guidelines recommend the use of cytoreduction therapy and low-dose aspirin (e.g., ASA 81 mg daily) to decrease the risk of thrombotic events. However, use of low-dose aspirin is based on limited evidence and is associated with a significant failure rate. Thromboprophylaxis with low-dose direct oral anticoagulants (e.g., apixaban 2.5 mg BID) is an appealing option in MPN, specifically when patients carry the JAK2 mutation, based on the pathophysiology of thrombus formation associated with this driver mutation. In other populations, thromboprophylaxis with a low-dose direct oral anticoagulant has been associated with a reduced risk of arterial and venous thrombotic complications, when compared to low-dose aspirin. Hence, we conducted a pilot trial to assess the feasibility of conducting a randomized controlled trial evaluating the efficacy and safety of apixaban (2.5 mg BID) compared to aspirin (81 mg daily) to prevent thrombotic complications in patients with JAK2-positive MPN (JAK2MPN). Methods: This was a multi-centre, prospective, open-label, blinded endpoint pilot trial (NCT04243122), conducted in three Canadian centers (Ottawa, Calgary, Sherbrooke). Adult patients with a confirmed diagnosis of polycythemia vera, JAK2-positive essential thrombocythemia or JAK2-positive pre-fibrotic myelofibrosis (per local clinical definitions) requiring low-dose aspirin for thromboprophylaxis were eligible. Both patients with an incident diagnosis of JAK2MPN (defined as diagnosed within 1 year) and patients with prevalent disease were targeted for recruitment. Exclusion criteria included a contraindication to thromboprophylaxis or the need for a specific anticoagulant or non-aspirin anti-platelet agent. Patients with a prior history of venous thromboembolism were eligible if they had completed a minimum of 6 months of anticoagulation therapy. Participants were randomized 1:1 to receive apixaban 2.5mg BID or aspirin 81mg daily, along with cytoreductive therapy (per guidelines). The study treatment duration was 6 months. Follow-up occurred at 3, 6 and 7 months after allocation of the study medication. The primary study outcome for feasibility was the monthly recruitment rate per study site over a 6-month follow-up period. Secondary outcomes included rates of thrombotic and bleeding complications. The total estimated sample size was 44 participants (22 per arm). Due to the COVID-19 pandemic, not all sites were able to start recruitment at the same time and the total recruitment period spanned over 24 months. Results: During this 24-month recruitment period, 93 JAK2MPN patients were screened for eligibility. Of these, 69 were eligible and 64% of eligible patients consented to participate. We therefore recruited 44 participants, for a recruitment rate of 0.8 patient per centre per month. Baseline characteristics of participants are presented in Table 1. A total of 29 prevalent cases and 15 incident cases were included. Secondary efficacy, safety, and feasibility outcomes (relating to thrombotic events, bleeding complications, and study compliance) will be available at the ASH Meeting, since all participants will have completed the 6-month treatment duration by October 2023. Discussion: Despite the challenges of the COVID-19 pandemic, we have recruited 100% of our target population. Given the chronicity of MPN, most outpatient clinics functioned remotely during the pandemic, precluding recruitment. Nevertheless, by adapting to the realities of the pandemic, we achieved our recruitment target demonstrating feasibility of a larger trial. The strategies adopted during this pilot trial to recruit participants, such as active screening of clinic lists for potential participants and direct communication with MPN specialists, will be applied to our larger scale trial. Conclusion: This pilot trial demonstrated the feasibility of conducting a large-scale trial evaluating the superiority of apixaban over aspirin for the thromboprophylaxis of JAK2MPN patients. As JAK2MPN are rare diseases, we have partnered with counterparts in France to conduct an international study on the efficacy and safety of direct oral anticoagulant thromboprophylaxis in JAK2MPN patients.

A Phase 3b, Randomized, Open-Label, Parallel Group, Multicenter Study to Assess Efficacy, Safety, and Tolerability of Two Dosing Regimens of Ropeginterferon Alfa-2b-Njft (P1101) in Adult Patients with Polycythemia Vera

Background and Significance: Polycythemia vera (PV), the most common chronic myeloproliferative neoplasm in the United States, is a long-term, debilitating, life-threatening cancer with limited treatment options. Most patients with PV receive phlebotomy and low-dose aspirin to prevent thrombosis. Cytoreductive therapy is recommended for high-risk and in some low-risk patients. Ropeginterferon alfa-2b-njft (P1101) is the first and only FDA-approved interferon for treating PV regardless of patients' risk category or past treatment history. The FDA-approved dosing for ropeginterferon alfa-2b-njft in patients with PV is a starting dose of 50 or 100 mcg every 2 weeks, with dose increases of 50 mcg every 2 weeks up to a maximum of 500 mcg. Clinical trial results confirmed high complete hematologic response (CHR) rates and molecular responses to ropeginterferon alfa-2b-njft, however, time to achieve CHR can take 6 months or longer because dose escalation to the highest maintenance dose ranged from 16 to 28 weeks. It is expected that the faster and simpler dosing scheme of 250-350-500 mcg, escalated every 2 weeks may allow patients to achieve complete hematologic responses significantly earlier with acceptable tolerability and safety. This notion was supported in a recently reported clinical study (Jin et al. Exp Hematol Onc 2023). To further assess the 250-350-500 mcg dosing regimen, this Phase 3b, randomized, open-label, parallel group, multicenter study (NCT05481151) of U.S. and Canadian patients will evaluate the efficacy and safety of ropeginterferon alfa-2b-njft when using the above described dose-escalation scheme directly compared with the approved dosing scheme. Study Design and Methods: The planned enrollment for this study is approximately 100 patients with PV aged ≥18 years from the U.S. and Canada. Patients will be randomized (1:1) into either the approved dosing regimen arm or the amended dose-escalation scheme arm (Figure 1). Inclusion criteria include diagnosis of PV according to the WHO 2008 or 2016 criteria, hemoglobin ≥10 g/dL for females, and hemoglobin ≥11 g/dL for males at screening, neutrophil count ≥1.5 × 10 9/L at screening. Exclusion criteria include: any contraindications to interferon alfa or hypersensitivity to interferon alfa, having stopped prior interferon alfa therapy due to low efficacy or poor tolerability, severe or serious diseases or any other diseases that the investigator determines may affect the subject's participation in this study, or the use of any investigational drug &amp;lt;4 weeks prior to the first dose of ropeginterferon alfa-2b-njft. Treatment-naïve patients and those pretreated with hydroxyurea (HU) will be included. Patients in the approved dosing arm will undergo HU tapering by 25% for the first 2 weeks, followed by 50% for weeks 3-4, 75% for weeks 5-6, and discontinuing completely during week 7 and onwards. Patients in the amended dose-escalation scheme arm are required to discontinue HU immediately upon initiation of ropeginterferon alfa-2b-njft. The primary efficacy endpoint is CHR (defined as hematocrit &amp;lt;45% in the absence of phlebotomy in the previous 12 weeks, white blood cell count ≤10 × 10 9/L, and platelets ≤400 × 10 9/L) at Week 24. Secondary endpoints include time to CHR, proportion of patients in CHR at Weeks 8, 12, 16, 20, 24, 36, and 48; time to maintenance dose (stable dose for 3 consecutive doses); and time to freedom from phlebotomies. The core treatment period will be 24 weeks followed by a 24-week extension period and a 4-week safety follow-up. Ropeginterferon alfa-2b-njft (P1101) will be provided in single-use 500-mcg prefilled syringes for subcutaneous administration every 2 weeks. The approved dosing arm will initiate with a starting dose of 100 mcg (Day 0) and increase by 50-mcg every 2 weeks up to a maximum dose of 500 mcg. The amended dosing arm will initiate with a starting dose of 250 mcg (Day 0), increase to 350 mcg at Week 2, and increase to a maximum of 500 mcg at Week 4. Dose adjustments will be allowed if safety or tolerability concerns arise. Cochran-Mantal-Haenszel test stratified by investigator sites will be used for analyzing the primary efficacy endpoint at Week 24. General statistical summaries will be applied to primary and secondary endpoints. For categorical variables, frequency and percentage will be presented with a 95% confidence interval.

Real-World Analysis of Thromboembolic Event Rates in Patients in the United States with Polycythemia Vera

Background:Polycythemia vera (PV) is a myeloproliferative neoplasm associated with an increased risk of thromboembolic events (TEs). PV patients are characterized based on their risk for TEs as low-risk (age &amp;lt;60 without prior history of TE) or high-risk (age ≥60 and/or prior history of TE). Observational studies have shown higher rates of TEs in PV patients compared to matched controls (14.3 vs 4.9/1000 patient years, or PY), with rates as high as 40% in patients with PV (Goyal et al., Blood. 2014;124:4840; Griesshammer et al., Ann Hematol. 2019;98:1071-82; Pemmaraju et al., Leuk Res. 2022;115:106809). We assessed the rate of arterial and venous TEs in a large cohort of low- and high-risk PV patients. Methods:We conducted a real-world, retrospective cohort study using Optum's de-identified Market Clarity Data, which includes electronic health records (EHR) on 105 million US patients between 2007-2019. Eligible patients were ≥18 years [yrs] 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 (12/31/2019). Patients with a pre-index diagnosis of secondary polycythemia, leukemia, myelodysplastic syndrome, myelofibrosis, or stem cell transplant were excluded. Patients were stratified into three groups based on risk status at index: low-risk (age &amp;lt;60 without prior history of TE), age-based high-risk (age &amp;gt;60 without prior history of TE) and event-based high-risk (prior history of TE). As outcomes, TEs were identified at the first occurrence of a diagnosis code for a TE in EHR during the post-index period. Descriptive statistics were used to characterize the proportion of patients with TEs and event rates per 1000 PY. Kaplan-Meier analysis was used to evaluate the probability of TE-free survival among patients in the three risk groups at various time points. Patients were censored at death or last engagement date. Results:The total study cohort included 20,089 PV patients (mean age, 63.0 yrs; 57.8% male; 88.6% Caucasian). Approximately one-third (34.4%; 6909 patients) were low-risk, 49.4% (9924 patients) were age-based high-risk, and 16.2% (3256 patients) were event-based high-risk. Among 17,402 patients with pre-index medication data, 16.0% (n=2777) received hydroxyurea (HU) pre-index. HU usage was highest in age-based high-risk patients (21.8%) followed by event-based high-risk (20.0%) and low-risk patients (5.8%). Median follow-up period was 4.3 yrs (IQR, 2.4-5.9). Incidence of TEs was assessed within patient groups (Table 1). Overall, 25.1% (5035/20,089) of patients with PV experienced at least one TE during the post-index period. Incidence of TEs was highest among event-based high-risk patients (50.2%; 1634/3256), followed by age-based high-risk (25.0%; 2480/9924) and low-risk patients (13.3%; 921/6909). The rate of post-index TEs was more than triple for event-based high-risk patients vs. age-based high-risk patients (206 vs. 68/1000 PY) and nearly 7 times higher vs. low-risk patients (206 vs. 31/1000 PY). The rate of TEs was more than double for age-based high-risk patients vs. low-risk patients (68 vs. 31/1000 PY). Incidence of arterial and venous TEs was assessed across the total cohort (Table 1). The most common arterial events were stroke (7.1%) and MI/ACS (6.4%). The most common venous events were DVT/deep thrombophlebitis (8.1%) and pulmonary embolism (4.5%). Kaplan-Meier analysis indicated that at ≈2.5 yrs (1000 days) post-index, TE-free survival was ≈90% for low-risk, ≈80% for age-based high-risk, and ≈55% for event-based high-risk patients (Figure 1). At ≈5.5 yrs (2000 days) post-index, TE-free survival had fallen to ≈85% for low-risk, ≈70% for age-based high-risk, and ≈40% for event-based high-risk patients. The downward trend continued until the end of the data period. Conclusion: Findings from this real-world analysis indicate that PV patients experience high rates of arterial and venous TEs. Event-based high-risk patients have a substantially lower probability of TE-free survival compared with age-based high-risk and low-risk patients. While patients with a prior history of TE have the highest thromboembolic risk, all patients with PV are at high risk of TE, indicating an unmet need for reduction of thromboembolic risks.

A Deep Learning-Based Pathomics Methodology for Quantifying and Characterizing Nucleated Cells in the Bone Marrow Microenvironment

Introduction: The overall cellularity of the bone marrow (BM) microenvironment is a WHO criterion for differentiating BCRABL- myeloproliferative neoplasms (MPNs) like polycythemia vera (PV) and myelofibrosis (MF) [1]. However, manual assessment by hematopathologists is subjective, not scalable, and only records a single global measure, disregarding BM regional differences. Leveraging pathology slide scanners and deep learning (DL) can address these limitations and reveal valuable insights into MPN subtypes and treatment effects. Despite its potential, computational pathology (Pathomics) in this area remains understudied [2-3]. Methods: After institutional review from Stony Brook University and Weill Cornell Medicine (WCM), we identified 54 patients (pts) with a manually confirmed PV diagnosis (dx) at WCM (17% newly dx'ed, 61% treated, 17% disease progression). The dataset includes hematoxylin &amp; eosin (H&amp;E) stained whole slide images (WSIs), labs, molecular studies, and pathology report elements (reference standard for biopsy core size and cellularity). Numeric cellularity measures the ratio of hematopoietic cells to fat cells and excludes inevaluable trabecular bone. Normal cellularity ranges from (100-pt age [y])±20% and PV is characterized by hypercellularity. We evaluated three DL algorithms for nuclear segmentation: 1) Our U-Net model trained on 5B nuclei from 10 cancer types [4], 2) HistoCartography (HC): a graph neural network trained on 235K nuclei (PanNuke/MoNuSac datasets) [5], and 3) CellPose (CP): a gradient-driven U-Net model trained on 1K nuclei of varied modalities [6]. A color/morphology-based segmenter identified fat cells and evaluable BM regions, excluding vessels/tissue tears. Cellular characteristics (shape, texture, color) were computed and clustered by k-nearest neighbors (kNN) and k-means to explore differences between PV stages. A tissue-based approach for cellularity estimation derived the proportion of non-fat tissue to evaluable regions. A cell-based approach derived the proportions of nucleated cell and fat cell areas. The study calculated mean differences between biopsy core size estimates, assessed correlation (r) and intra-class correlation (ICC) for numeric cellularity estimates, and Cohen's kappa (κ) for categorical cellularity estimates. Results: Measured and estimated biopsy core sizes differed by an acceptable margin (3±4 mm). Tissue-based cellularity estimator results: r=0.2, ICC=0.0, κ=0.2. Cell-based cellularity estimator result: our approach (r=0.7, ICC=0.6, κ=0.7), HC (r=0.7, ICC=0.5, κ=0.6), and CP (r=0.2, ICC=0.2, κ=0.7). Cell size clusters aligned with known distributions in PV, with the prominent Int1 class (5.1-9μm) likely containing erythrocytes and myeloid progenitors. Overall and cell-sized cellularity heatmaps visualize regional differences (Figure 1). K-means clustering separated new and progressing PV (Figure 2). Discussion: DL and classical image analysis were employed to segment nucleated cells, fat cells, and other evaluable regions of hematopoietic tissue. Extracting shape, texture, and color features from segmented nuclei enhances BM microenvironment characterization. This pilot study resulted in a practical and interpretable Pathomics pipeline and downstream analytics as a proof of concept for hypothesis-driven research. Future directions involve applying these insights to a large cohort of diagnosis WSIs from other MPN subtypes and correlating findings with other tools, like immune cell detection models.

Sodium-Glucose Co-Transporter-2 Inhibitor Use in the Setting of Myeloproliferative Neoplasms: Impact on Hemoglobin/Hematocrit Levels and Thrombosis Risk

Background: Sodium-glucose co-transporter-2 inhibitors (SGLT-2I) are FDA-approved for diabetes mellitus, heart failure and chronic renal disease. Clinical trials on their anti-diabetic and cardiorenal protective effects showed an association with erythrocytosis. We have previously reported on the benign nature of SGLT-2I associated JAK2-unmutated erythrocytosis ( Blood 2021). Recently, we described the same phenomenon in the setting of a previously unrecognized myeloproliferative neoplasm (MPN), which led to unmasking of underlying MPN and thrombosis in 3 (33%) of 9 informative cases ( AJH 2023). The main objective of the current study was to assess the erythropoietic and thrombotic impact of SGLT-2I therapy in patients with a well-established MPN diagnosis, prior to treatment initiation. Methods: The Mayo Clinic MPN database was queried to identify patients prescribed SGLT2-I after diagnosis of essential thrombocythemia (ET), polycythemia vera (PV) or myelofibrosis (MF). Baseline Hgb/Hct at SGLT-2I initiation, peak Hgb/Hct, absolute change in Hgb/Hct levels, and thrombosis during treatment were recorded. Results: SGLT-2I use in essential thrombocythemia Eleven patients with ET (median age; 72 years, 55% males, 73% JAK2 mutated, 64% with thrombosis history) received SGLT-2I. Active treatments included aspirin ( n=10), cytoreductive therapy ( n=10) and systemic anticoagulation ( n=4). All 11 patients displayed increase in Hgb/Hct following SGLT-2I treatment. Baseline median (range) values for Hgb/Hct were 12.8 g/dL (9.5-14.9)/38.9% (30.3-44.6); median (range) peak Hgb/Hct levels during SGLT-2I therapy, were 14.5 g/dL (11-16.4)/44.4% (34.8-51.1), with median (range) increase in Hgb/Hct of 1.5 g/dL (1-4)/5.1% (2.6-13.8); 2 patients (18%), exceeded the proposed ICC Hgb/Hct diagnostic threshold for PV (Patient 7 and 8) (Figure 1). JAK2 mutation/VAF (p=0.54/ 0.20), or serum erythropoietin (Epo) (p=0.48) did not correlate with changes in Hgb/Hct levels. One patient experienced thrombosis, despite treatment with hydroxyurea and aspirin and Hgb/Hct levels below the threshold of concern (11.4 g/dL/37.7%). SGLT-2I use in polycythemia vera Nine patients with PV (median age 74 years, 66% males, JAK2 median VAF 14%, two patients with thrombosis history) received SGLT-2I. Concomitant treatments included aspirin ( n=9), cytoreductive therapy ( n=8), and systemic anticoagulation ( n=3). Phlebotomy intensity, defined as the number of phlebotomies, six months prior to and after SGLT-2I initiation, ranged from 0-3 and 0-12, respectively. Documented Hgb/Hct levels showed an increase in all 9 cases with baseline median (range) values for Hgb 14.1 g/dL (10.5-15.9) and Hct 42.7% (33.3-49.2) and peak median (range) values for Hgb/Hct, 15.4 g/dL (11.2-19.9)/46.7% (35.9-63.3). JAK2 VAF (p=0.85), and serum Epo (p=0.43) did not correlate with increase in Hct. Figure 2 highlights five patients (56%) with Hct exceeding 45% while on SGLT-2I; two patients (22%) had increased phlebotomy requirements; 6-month pre/post SGLT-2I phlebotomies for patient 5 and 9 were 3 and 6, and 0 and 12, respectively. Patient 9, experienced thrombosis in the context of uncontrolled Hgb/Hct level at 19.9 g/dl/63.3% and absence of cytoreductive therapy. SGLT-2I use in myelofibrosis Eight patients with myelofibrosis (primary 6, post-ET 2; median age 71 years; 50% males; 63% JAK2 mutated; MIPSS-70 2.0 int/high 6; on ruxolitinib 4),received SGLT-2I. Baseline median (range) values for Hgb/Hct were 10.6 g/dL (8.2-14.7)/27.5% (33.8-45.9); two (25%) patients displayed anemia with Hgb 8-10 g/dl. Peak median (range) values for Hgb/Hct were 11.5 g/dL (10.2-16.1)/35.3% (31.8-49.8), with median (range) baseline increase in Hgb/Hct of 1.6 g/dL (0.7-3.8)/4.3% (1-7.5). Patient 2 and 4 with baseline Hgb 8.2 g/dl and 9.4 g/dl, and not receiving ruxolitinib, had Hgb increase of 2 g/dl and 1 g/dl, respectively (Figure 3). One thrombotic event occurred during therapy with Hgb/Hct level of 11.6 g/dl/37.3%. Conclusion: The current study suggests that SGLT-2I therapy in MPN patients leads to increase in Hgb/Hct levels, regardless of disease subtype, and in some cases surpass the PV diagnosis and thrombosis risk thresholds. These observations mandate increased awareness to secure patient safety and diagnostic accuracy. The erythropoietic effect of SGLT-2I in MF suggests its potential use for MF-associated anemia.

Rusfertide Improves Markers of Iron Deficiency in Patients with Polycythemia Vera

Background: Polycythemia vera (PV) is a chronic myeloproliferative neoplasm characterized by erythrocytosis defined by an acquired increase in hemoglobin (Hb)/hematocrit (HCT). Disease complications are associated with increased blood viscosity, cardiovascular/thrombotic events and iron deficiency (Marchioli et al. N Engl J Med. 2013;368:22-33). Most patients with PV are iron deficient and therapeutic phlebotomy may exacerbate iron deficiency (Ginzburg et al. Leukemia. 2018;32:2105-16). Methods:PTG-300-08 (clinicaltrials.gov NCT04767802, PACIFIC study) is an open-label, 52-week, phase 2 study that investigated the efficacy and safety of rusfertide in Asian patients with poor hematocrit (HCT) control as noted by HCT &amp;gt;48%. Treatment was initiated with 40 mg rusfertide subcutaneously (SC) twice a week. Once HCT was &amp;lt;45%, the treatment was changed to 40 mg once a week with subsequent dose adjustments allowed to maintain HCT &amp;lt;45%. In addition to HCT and erythrocyte morphology (mean corpuscular volume, or MCV), biomarkers reflective of iron biology, such as hepcidin, erythroferrone (ERFE), erythropoietin (EPO), and soluble transferrin receptor (sTfR) were measured at baseline, Week 4, 16, and 32 following initiation of rusfertide treatment. To examine the effect of rusfertide on serum iron, patients were stratified by baseline ferritin levels to examine patients who were iron deficient (ferritin ≤20 µg/L) compared to patients who had normal iron (ferritin &amp;gt;20 µg/L). Results: Twenty patients (15 males, 5 females), average age 56.7 (SD, 9.12) years and average weight 65 (10.9) kg were enrolled. Thirteen patients (65%) were low risk and 7 (35%) were high risk, all based on age. No patients had a prior history of thromboembolic events. Mean duration since PV diagnosis was 4.2 (3.83) years. Rusfertide rapidly and robustly reduced mean HCT and sustained HCT &amp;lt;45% for the duration of treatment, and ferritin, TSAT and MCV increased (Table 1). At baseline, 30% of subjects had serum ferritin levels below 20 µg/L, with all subjects achieving and sustaining ferritin levels above 20 µg/L by Week 4 following initiation of rusfertide treatment. Table 1 also summarizes the biomarkers related to iron indices. Median hepcidin concentrations increased, median EPO concentration was below and remained below the limit of detection, and ERFE concentration decreased modestly with rusfertide dosing consistent with reduced erythropoietic drive. Among patients with evidence of baseline iron deficiency (ferritin &amp;lt;20 µg/L), rusfertide normalized iron levels while iron levels remained stable in rusfertide patients with normal iron levels at baseline (Figure 1). Similarly, patients with iron deficiency had low MCV at baseline (Figure 1) which increased following initiation of rusfertide treatment. In patients with normal iron levels, MCV remained stable in the normal range (&amp;gt;80 fl). Conclusions: Treatment with rusfertide resulted in rapid, robust, and sustained reduction in HCT levels in PV patients with elevated HCT levels at baseline. Treatment resulted in normalization of iron parameters as noted by increases in ferritin, and normalization of serum iron and MCV in patients who were iron deficient at baseline. Improvements in iron deficiency following rusfertide are suggestive of clinical benefits and merit further investigation. This analysis confirms the general understanding that managing iron deficiency in PV remains an unmet need.