Philadelphia chromosome-negative classical myeloproliferative neoplasms: revised management recommendations from European LeukemiaNet

A Toolkit for Healthcare Transition for Adolescents With Classical Myeloproliferative Neoplasms

Classical myeloproliferative neoplasms (MPNs) are being identified more frequently in adolescents. There is no guidance on the healthcare transition of young MPN patients from pediatric to adult medicine. Therefore, we convened an international panel of experts in both pediatric and adult MPN care to develop three tools to facilitate high-quality healthcare transition: a physician education tool, a transition readiness assessment tool, and a consensus statement of practice recommendations to ensure a more seamless transition in the care adolescents receive. These tools can help ensure a better healthcare transition for young patients. The next steps include evaluating the readiness assessment tool with adolescent patients.

Impact of treatment for adolescent and young adults with essential thrombocythemia and polycythemia vera

Essential thrombocythemia (ET) and polycythemia vera (PV) are rare in adolescent and young adult (AYA). These conditions, similar to those in older patients, are linked with thrombotic complications and the potential progression to secondary myelofibrosis (sMF). This retrospective study of ET and PV patients diagnosed before age 25 evaluated complication rates and impact of cytoreductive drugs on outcomes. Among 348 patients (278 ET, 70 PV) with a median age of 20 years, the of thrombotic events was 1.9 per 100 patient-years. Risk factors for thrombosis included elevated white blood cell count (>11 × 109/L) (HR: 2.7, p = 0.012) and absence of splenomegaly at diagnosis (HR: 5.7, p = 0.026), while cytoreductive drugs did not reduce this risk. The incidence of sMF was 0.7 per 100 patient-years. CALR mutation (HR: 6.0, p < 0.001) and a history of thrombosis (HR: 3.8, p = 0.015) were associated with sMF risk. Interferon as a first-line treatment significantly improved myelofibrosis-free survival compared to other treatments or the absence of cytoreduction (p = 0.046). Although cytoreduction did not affect thrombotic event, early interferon use reduced sMF risk. These findings support interferon use to mitigate sMF risk in AYA ET and PV patients.

Prediction of resistance to hydroxyurea therapy in patients with polycythemia vera: a machine learning study (PV-AIM) validated in a prospective interventional phase IV trial (HU-F-AIM)

Polycythemia vera (PV) is a myeloproliferative neoplasm associated with increased thromboembolic (TE) risk and hematologic complications. Hydroxyurea (HU) serves as the most frequently used first-line cytoreductive therapy worldwide; however, resistance to HU (HU-RES) develops in a significant subset of patients, leading to increased morbidity and necessitating alternative treatments. This study, part of the PV-AIM project, employed machine learning techniques on real-world evidence (RWE) from the Optum® EHR database containing 82.960 PV patients to identify baseline predictors of HU-RES within the first 6-9 months of therapy. Using a Random Forest model, the study analyzed data from 1850 patients, focusing on laboratory parameters and clinical characteristics. Key predictive markers included red cell distribution width (RDW) and hemoglobin (HGB), showing the strongest association with HU-RES. A synergistic interaction between RDW and HGB was identified, enabling TE risk stratification. This study provides a robust framework for early detection of HU-RES using readily available clinical data, facilitating timely intervention. These findings underscore the importance of personalized treatment approaches in managing PV and highlight the utility of machine learning in enhancing predictive accuracy and clinical outcomes. Based on the results of PV-AIM we initiated an open-label, prospective, single-arm, interventional, phase IV study (HU-F-AIM) evaluating HU-resistance/intolerance. Validation of predictive biomarkers may facilitate identification of patients at risk of HU resistance who may benefit from alternative treatment options, possibly preventing ongoing phlebotomy during HU treatment, a frequent therapeutic choice in high-risk PV associated with early disease progression and increased thromboembolic complications. We propose an updated terminology that differentiates between true molecular resistance and clinical resistance, that may indicate the requirement for alternative therapeutic strategies.

Polycythaemia vera

Polycythaemia vera (PV) is a haematological malignancy in the myeloproliferative neoplasm family. PV is typically characterized by erythrocytosis and often leukocytosis and thrombocytosis1. Clinical features include reduced life expectancy due to hazards of thrombosis (often in atypical sites), haemorrhage and transformation to myelofibrosis and less frequently to a form of acute myeloid leukaemia called blast phase. Almost two decades ago, the JAK2V617F mutation in exon 14 of JAK2 was described, and is known to be present in more than 95% of patients with PV. Testing for the JAK2V617F mutation is used in the diagnosis of PV, and the quantity of the mutation (that is, the variant allele frequency) is linked to prognosis and the risk of complications. As such, reduction of JAK2V617F variant allele frequency is currently being evaluated as a treatment target. Recommendations for PV treatment include control of vascular risk factors, therapeutic phlebotomy and low-dose aspirin in all patients. Currently, patients at higher risk of thrombosis (aged over 60 years and/or with a history of thrombosis) are offered cytoreductive agents. Hydroxyurea or interferons remain the preferred first-line cytoreductive agents, with the JAK1 and JAK2 inhibitor, ruxolitinib, currently approved for the treatment of patients who are resistant to, or intolerant of, hydroxyurea. Future recommendations might be to treat the majority of patients with these agents as long-term benefits of treatment begin to emerge.

How I treat patients with low-risk polycythemia vera who require cytoreduction

ABSTRACT

Polycythemia vera (PV) was first described by Louis Henri Vaquez in 1892. It is a chronic hematological malignancy that affects both older and young patients. Perhaps because of lack of a curative treatment and the perceived toxicities of prior therapies, our focus in the past was to intensify treatment only for patients at higher risk of thrombosis. Recent triggers to challenge this approach include the following: a recognition that low-risk PV is not "no risk," our ability to better recognize patients who would benefit from more intensive therapy from the perspective of thrombosis, and data showing that some treatments may reduce risk of transformation to myelofibrosis. Furthermore, there is emergent evidence that molecular monitoring may identify an improvement in disease state translating to improved overall survival. Here, we describe clinical situations that would trigger the use of cytoreductive treatment for patients with low-risk PV as well as our approach to choosing a specific cytoreductive agent and how to effectively monitor treatment.

New approaches to standard of care in early-phase myeloproliferative neoplasms: can interferon-α alter the natural history of the disease?

The classical BCR::ABL-negative myeloproliferative neoplasms (MPN) include polycythemia vera, essential thrombocythemia, and primary myelofibrosis. They are acquired clonal disorders of hematopoietic stem cells leading to hyperplasia of one or several myeloid lineages. MPN are caused by three main recurrent mutations, JAK2V617F and mutations in the calreticulin (CALR) and thrombopoietin receptor (MPL) genes. Here, we review the general diagnosis, the complications, and the management of MPN. Second, we explain the physiopathology of the natural disease development and its regulation, which contributes to MPN heterogeneity. Thirdly, we describe the new paradigm of MPN development highlighting the early origin of driver mutations, decades before the onset of symptoms, and the consequence of early detection of MPN cases in the general population for prompt diagnosis and better medical management. Finally, we present interferon-α therapy as a potential, early disease-modifying drug after reporting its good hematologic and molecular efficacies in polycythemia vera, essential thrombocythemia, and early myelofibrosis in clinical trials as well as its mechanism of action in pre-clinical studies. As a result, we may expect that, in the future, MPN patients will be diagnosed very early during the course of disease and that new selective therapies under development, such as interferon-α, JAK2V617F inhibitors and CALRmut monoclonal antibodies, will be able to intercept the mutated clones.

Safety and Efficacy of Busulphan Based on Dosing Patterns in the Real-World Management of Myeloproliferative Neoplasms

Introduction

Myeloproliferative neoplasms (MPNs), such as polycythaemia vera (PV), essential thrombocythemia (ET) and myelofibrosis (MF), are primarily treated by managing blood counts to reduce the thrombotic risk using cytoreductive agents. Busulphan, an oral alkylating agent, has been historically used for MPN management due to its myelosuppressive effects, but concerns about its risk of leukaemic transformation have limited its use.

Methods

This real-world retrospective study evaluated the safety and efficacy of busulphan in 115 MPN patients across 13 UK hospitals. Responses in patients with ET and PV only were assessed using European LeukemiaNet (ELN) criteria.

Results

With a median age of 78 years, the overall response rate was 78.1%, with 29% of PV and 18% of ET patients achieving complete responses. Dosing regimens were similarly distributed between repeated single doses of busulphan (31%), courses of treatment lasting 1-4 weeks (30%) and continuous therapy for more than 4 weeks (35%). No cases of disease progression to acute leukaemia or myelofibrosis were recorded during the median follow-up of 23 months. Adverse events were infrequent, with fatigue and cytopaenia being the most common (4% each).

Conclusion

Busulphan demonstrated a favourable safety profile and is a viable cytoreductive option, particularly for elderly patients who are intolerant to hydroxycarbamide.

Trial Registration

The authors have confirmed clinical trial registration is not needed for this submission.

Pathogenesis and management of high molecular risk myeloproliferative neoplasms

Classical myeloproliferative neoplasms (MPN) are clonal stem cell disorders characterized by driver mutations that affect the constitutive activation of JAK-signaling. Mutations additional to an MPN-driver occur in a large number of patients and have been shown be associated with disease presentation and progression. In this review, we outline the current hypotheses regarding how clonal evolution in MPN is thought to occur and the functional mechanisms as to how concomitant somatic mutations (i.e., mutations in genes other than the 'driver' genes) contribute to disease progression. We discuss the definitions of high molecular risk MPN, provide an overview of how concomitant mutations influence the clinical management of MPN and suggest how the rapidly developing genetic risk stratification can be utilized to improve clinical outcomes.

Thrombosis at Unusual Sites: Focus on Myeloproliferative Neoplasms and Paroxysmal Nocturnal Hemoglobinuria

Patients with thrombosis at an unusual site will need to be explored for rare causes of thrombosis. Two of these rare causes include myeloproliferative neoplasms (MPNs) and paroxysmal nocturnal hemoglobinuria (PNH). It is important not to overlook these causes, since they require specific management, in addition to antithrombotic treatment (anticoagulants, antiplatelet agents). Unusual sites of venous thrombosis include upper extremity veins, splanchnic veins, cerebral veins, and retinal veins, and unusual sites of arterial thrombosis include renal, adrenal, splenic and mesenteric arteries, and intracardiac and aortal locations. Suspicion for MPN and PNH should be raised if there are concomitant abnormalities, such as elevated or decreased blood cell counts or splenomegaly. Diagnosis of MPN and PNH should include JAK2V617F mutational screening as well as flow cytometric assessment of GPI-anchored proteins in the peripheral blood, respectively. Specific treatments for MPN may include phlebotomy or cytoreductive drugs such as hydroxyurea, anagrelide, pegylated interferon-alpha, or Janus kinase inhibitors. Drugs used for PNH treatment include terminal complement inhibitors, such as eculizumab and ravulizumab, as well as proximally acting inhibitors such as pegcetacoplan or iptacopan. Patients with MPN and PNH are at high risk for thrombosis during their entire lifetime and should thus be followed by specialists experienced in the care of these diseases.

Essential Thrombocythemia: A Review

Importance

Essential thrombocythemia, a clonal myeloproliferative neoplasm with excessive platelet production, is associated with an increased risk of thrombosis and bleeding. The annual incidence rate of essential thrombocythemia in the US is 1.5/100 000 persons.

Observations

Patients with essential thrombocythemia have a persistent platelet count of 450 × 109/L or greater. The differential diagnosis includes myeloproliferative neoplasms (polycythemia vera, primary myelofibrosis, chronic myeloid leukemia); inflammatory conditions such as rheumatoid arthritis and systemic lupus erythematosus; infections; splenectomy; iron deficiency anemia; and solid tumors such as lung cancer. Approximately 90% of individuals with essential thrombocythemia have genetic variants that upregulate the JAK-STAT (signal transducer and activator of transcription 5) signaling pathway, including Janus kinase 2 (JAK2, 64%), calreticulin (CALR, 23%), and myeloproliferative leukemia virus oncogene (MPL, 4%). The median age at diagnosis of essential thrombocythemia is 59 years. The median overall survival exceeds 35 years in those diagnosed at 40 years or younger. Patients with essential thrombocythemia are at increased risk of arterial thrombosis (11%), venous thrombosis (7%), and hemorrhagic complications (8%). Thrombosis risk is increased among those with a history of thrombosis, age older than 60 years, a JAK2 gene variant, and cardiovascular risk factors (eg, hypertension, diabetes mellitus, hyperlipidemias, tobacco use). Use of aspirin (81-100 mg/d) is suggested for most patients with essential thrombocythemia to lower thrombosis risk. In a retrospective study of 300 affected patients with a low thrombosis risk (younger than 60 years with no prior thrombosis), those not taking aspirin (100 mg/d) had a risk of arterial thrombosis of 9.4/1000 patient-years and a venous thrombosis risk of 8.2/1000 patient years; cardiovascular risk factors were associated with a higher risk of arterial thrombi (incidence rate ratio, 2.5 [95% CI, 1.02-6.1]), and a JAK2 gene variant was associated with increased risk of venous thrombosis (incidence rate ratio, 4.0 [95% CI, 1.2-12.9]). In a randomized trial of 114 patients at higher risk for thrombosis (age older than 60 years or a prior thrombotic event), cytoreduction with hydroxyurea significantly lowered the risk of arterial or venous thrombotic events compared with no cytoreductive therapy (3.6% vs 24%; P < .01). At a median of 8.5 years from diagnosis, approximately 10% of patients with essential thrombocythemia develop myelofibrosis and about 3% develop acute myeloid leukemia.

Conclusions

Essential thrombocythemia is a rare clonal myeloproliferative neoplasm associated with an increased risk of venous and arterial thrombosis, hemorrhage, myelofibrosis, and acute myeloid leukemia. Based on individual risk factors for thrombosis, persons with essential thrombocythemia may be treated with low-dose aspirin, either alone or in combination with a cytoreductive drug such as hydroxyurea.

Survey of Clinical Practice in Chronic Myeloproliferative Neoplasms in Croatia: A Study by the MPN Working Group Party of the Croatian Cooperative Group for Hematologic Diseases (KROHEM)

Background/Objectives: Chronic myeloproliferative neoplasms (MPNs), essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis (MF), are hematopoietic stem cell disorders characterized by increased proliferation of mature myeloid cells, a chronic inflammatory state, and high cardiovascular risk. The diagnostic and therapeutic landscape in the field of MPNs is rapidly evolving. Therefore, it is important to assess the behavior of physicians involved in the management of MPN patients to gain insight into how they embrace the current diagnostic and treatment landscape in real-life settings. Methods: An online anonymous survey consisting of 50 questions regarding their MPN practice and divided into four major domains (physician characteristics, diagnostic procedures, therapeutic decisions, and patient follow-up) was sent through the Croatian Cooperative Group for Hematologic Diseases' (KROHEM's) e-mailing list to all Croatian hematologists. Results: Thirty-one out of ninety adult hematologists (34.4% response rate) from KROHEM responded to this survey. There was a very high rate of self-proclaimed abidance to current international diagnostic and therapeutic recommendations, with no major differences among academic and community practices. However, some areas of uncertainty have been highlighted, especially in the frequency of cytogenetic and molecular testing, as well as very low implementation of the Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) questionnaire in everyday practice. Conclusions: This study provides an important snapshot of the current MPN practice in Croatia. Similar studies from other countries are needed to provide a more detailed overview of real-life MPN practice globally.

[Advances in the diagnosis and treatment of thrombocytosis in children]

Thrombocytosis is a common condition in children, classified into primary and secondary types. Secondary thrombocytosis is mainly caused by factors such as infection, anemia, iron deficiency, trauma, or surgical intervention, and it typically occurs without severe thrombosis or bleeding events. Platelet counts can return to normal after control of the primary factors, with favorable clinical outcomes. Primary thrombocytosis is mainly caused by myeloproliferative neoplasms such as polycythemia vera, essential thrombocythemia, and myelofibrosis, often accompanied by gene mutations in hematopoietic cells. In children, clinical manifestations are atypical compared to adults, with few thromboembolic or bleeding events. No special treatment is required for patients who are asymptomatic or have mild symptoms, and it is recommended to regularly monitor platelet counts. Antiplatelet therapy with aspirin can be considered for patients at risk of thrombosis or those with extreme thrombocytosis, and cytoreductive therapy can be performed when necessary, but the toxicities and side effects of drugs should be closely monitored. At present, hydroxyurea, interferon-alpha, and anagrelide are commonly used for cytoreductive therapy. This article provides an overview of the etiology, classification, clinical manifestations, diagnosis, and treatment of childhood thrombocytosis to guide healthcare professionals in treatment decisions.

The Proteome Content of Blood Clots Observed Under Different Conditions: Successful Role in Predicting Clot Amyloid(ogenicity)

A recent analysis compared the proteome of (i) blood clots seen in two diseases-sepsis and long COVID-when blood was known to have clotted into an amyloid microclot form (as judged by staining with the fluorogenic amyloid stain thioflavin T) with (ii) that of those non-amyloid clots considered to have formed normally. Such fibrinaloid microclots are also relatively resistant to fibrinolysis. The proteins that the amyloid microclots contained differed markedly both from the soluble proteome of typical plasma and that of normal clots, and also between the diseases studied (an acute syndrome in the form of sepsis in an ITU and a chronic disease represented by Long COVID). Many proteins in the amyloid microclots were low in concentration in plasma and were effectively accumulated into the fibres, whereas many other abundant plasma proteins were excluded. The proteins found in the microclots associated with the diseases also tended to be themselves amyloidogenic. We here ask effectively the inverse question. This is: can the clot proteome tell us whether the clots associated with a particular disease contained proteins that are observed uniquely (or are highly over-represented) in known amyloid clots relative to normal clots, and thus were in fact amyloid in nature? The answer is in the affirmative in a variety of major coagulopathies, viz., venous thromboembolism, pulmonary embolism, deep vein thrombosis, various cardiac issues, and ischaemic stroke. Galectin-3-binding protein and thrombospondin-1 seem to be especially widely associated with amyloid-type clots, and the latter has indeed been shown to be incorporated into growing fibrin fibres. These may consequently provide useful biomarkers with a mechanistic basis.

Current myeloproliferative neoplasm scoring systems for clinical practice

ABSTRACT

BCR::ABL1-negative myeloproliferative neoplasms (MPNs) are clonal hematologic malignancies that are caused by the proliferation of myeloid cells that harbor a JAK-STAT pathway activating driver mutation. MPN management recommendations are based on the evaluation of different risks to prevent disease evolution-associated events while preserving patients' quality of life. Such risks can be common across all MPNs or specific to each subtype (polycythemia vera [PV], essential thrombocythemia [ET], prefibrotic myelofibrosis [MF], and primary MF). Patients with MF harbor the worse prognosis, and hematopoietic stem cell transplantation (HSCT) is the only curative treatment at the expense of a high rate of morbidity and mortality. Therefore, accurate scoring systems to estimate overall survival are crucial for the management of patients with MF and the selection for HSCT. In PV and ET, the prediction of vascular events is prioritized given their higher incidence and related morbidity and mortality. Finally, quality of life evaluation is important for all subtypes. To predict these risks and adapt MPN therapeutic strategies, clinical risk scores have been developed over the past decades and more recently have incorporated molecular risk factors for more accurate risk stratification. The large number of scoring systems available, combined with disease heterogeneity and the necessity to predict diverse outcomes, make it difficult for clinicians to choose the most appropriate score to evaluate their patients' risk in 2024. Here, we provide an overview of MPN disease evolution-associated event incidence and conduct an exhaustive comparative review of the scoring systems currently available for each risk. Finally, we propose an algorithm for the use of these scores in clinical practice in each MPN subtype.

Diagnosis and Treatment of Polycythemia Vera: A Review

Importance

Polycythemia vera (PV), a myeloproliferative neoplasm characterized by an increased red blood cell mass and increased risk of thrombosis, affects approximately 65 000 people in the US, with an annual incidence of 0.5 to 4.0 cases per 100 000 persons.

Observations

Erythrocytosis (hemoglobin >16.5 mg/dL in men or >16.0 mg/dL in women) is a required diagnostic criterion, although thrombocytosis (53%) and leukocytosis (49%) are common. Patients may have pruritus (33%), erythromelalgia (5.3%), transient visual changes (14%), and splenomegaly (36%) with abdominal discomfort. More than 95% of patients have a JAK2 gene variant, which helps distinguish PV from secondary causes of erythrocytosis, such as tobacco smoking or sleep apnea. Among 7 cohorts (1545 individuals), the median survival from diagnosis was 14.1 to 27.6 years. Prior to or at the time of PV diagnosis, arterial thrombosis occurred in 16% of patients and 7% had venous thrombotic events, which could involve unusual sites, such as splanchnic veins. PV is also associated with an increased bleeding risk, especially in patients with acquired von Willebrand disease, which can occur with extreme thrombocytosis (platelet count, ≥1000 × 109/L). All patients with PV should receive therapeutic phlebotomy (goal hematocrit, <45%) and low-dose aspirin (if no contraindications). Patients who are at higher risk of thrombosis include those aged 60 years or older or with a prior thrombosis. These patients and those with persistent PV symptoms may benefit from cytoreductive therapy with hydroxyurea or interferon to lower thrombosis risk and decrease symptoms. Ruxolitinib is a Janus kinase inhibitor that can alleviate pruritus and decrease splenomegaly in patients who are intolerant of or resistant to hydroxyurea. About 12.7% of patients with PV develop myelofibrosis and 6.8% develop acute myeloid leukemia.

Conclusions and Relevance

PV is a myeloproliferative neoplasm characterized by erythrocytosis and is almost universally associated with a JAK2 gene variant. PV is associated with an increased risk of arterial and venous thrombosis, hemorrhage, myelofibrosis, and acute myeloid leukemia. To decrease the risk of thrombosis, all patients with PV should be treated with aspirin and therapeutic phlebotomy to maintain a hematocrit of less than 45%. Cytoreductive therapies, such as hydroxyurea or interferon, are recommended for patients at high risk of thrombosis.

Fedratinib combined with ropeginterferon alfa-2b in patients with myelofibrosis (FEDORA): study protocol for a multicentre, open-label, Bayesian phase II trial

BACKGROUND

Myelofibrosis (MF) is a clonal haematopoietic disease, with median overall survival for patients with primary MF only 6.5 years. The most frequent gene mutation found in patients is JAK2V617F, causing constitutive activation of the kinase and activation of downstream signalling. Fedratinib is an oral selective JAK2 inhibitor. It has shown activity in MF and is well-tolerated, but combination with other therapies is likely needed to achieve clonal remission. Combining a JAK2 inhibitor with an interferon may be synergistic, as haematopoietic cells are activated from quiescence (a typical kinase resistance mechanism) rendering them more sensitive to inhibition. Ropeginterferon alfa-2b is a next generation pegylated interferon-α-2b with high tolerability and clinical activity in patients with MF, however, evidence of tolerability and activity in combination with fedratinib is lacking in this setting. The aim of the FEDORA trial is to assess tolerability, safety, and activity of fedratinib with ropeginterferon alfa-2b in patients with MF who require treatment to justify further investigation in a phase III trial.

METHODS

FEDORA is a single arm, multicentre, open-label, Bayesian phase II trial to assess tolerability, safety, and activity of fedratinib with ropeginterferon alfa-2b aiming to recruit 30 patients. Patients with JAK2V617F positive primary or secondary MF, who are aged ≥ 18 years, have intermediate-1 with palpable splenomegaly of > 5cm, intermediate-2, or high-risk disease according to the Dynamic International Prognostic Scoring System (DIPSS), and who require treatment are eligible. The primary outcome is tolerability, whereby the combination is deemed intolerable in a patient if drug-related toxicities in the first four months of treatment lead to: either drug being discontinued; delays in treatment exceeding 28 consecutive days; or death. FEDORA uses a within-patient dose escalation regimen to ensure each patient reaches a personalised dose combination that is acceptable.

DISCUSSION

FEDORA is using a Bayesian trial design and aims to provide evidence of the tolerability, safety, and activity of combining fedratinib with ropeginterferon alfa-2b upon which the decision as to whether a phase III trial is warranted will be based.

TRIAL REGISTRATION

EudraCT number: 2021-004056-42.

ISRCTN

88,102,629.

Cost-utility analysis of ropeginterferon alfa-2b to manage low-risk patients with polycythemia vera as compared to phlebotomy only in the Austrian healthcare system

Treatment of polycythemia vera (PV) aims to maintain hematocrit on target to reduce risk of thrombotic complications, while preventing disease progression to myelofibrosis (MF) and acute myeloid leukemia (AML). This analysis evaluated cost-effectiveness of adding ropeginterferon alfa-2b (ropegIFNα) to phlebotomy in patients with low-risk PV (those younger than 60 years without prior thrombosis), compared to phlebotomy alone. We combined a 12-month decision tree with a semi-Markov cohort model comparing ropegIFNα to the standard treatment from the Austrian healthcare system perspective over 30 years. Outcomes were quality adjusted life years (QALYs), costs, and incremental cost-utility ratio (ICUR). Model inputs were obtained from the phase 2 Low-PV study, additional published literature and from Austrian-specific cost databases. One-way and probabilistic sensitivity analyses (SA) assessed the robustness of findings. RopegIFNα led to 1,43 higher QALYs and 50.960 EUR overall higher costs compared to phlebotomy alone, with an ICUR of 35.525 EUR/QALY. Thrombosis, MF, and AML costs decreased for the ropegIFNα group by 12%, 30% and 16% respectively, due to the delayed complications onset and disease progression. In the one-way SA, ropegIFNα costs and discount rates had the greatest impact on results. The probabilistic SA showed a 100% probability of cost-effectiveness at willingness-to-pay threshold aligned to the Austrian GDP per capita. RopegIFNα is a cost-effective treatment option for patients with low-risk PV. These findings suggest that early treatment with ropegIFNα could ensure optimal resource allocation by preventing costly thrombotic events and progression to MF whilst increasing patient quality of life.

PARADIGM-PV: a randomized, multicenter phase 4 study to assess the efficacy and safety of ropeginterferon alfa-2b in patients with low- or high-risk polycythemia vera

Polycythemia vera (PV) is characterized by clonal hematopoietic stem or progenitor cells with constitutively active somatic mutation(s) in the Janus kinase 2 gene. Phlebotomy (Phl) and aspirin are often used alone for low-risk PV patients. However, data from the Low-PV study demonstrated that Phl and aspirin may not be adequate for patients. Therapeutic intervention with disease-modifying treatment appears to be beneficial for patients with PV regardless of the risk category. Ropeginterferon alfa-2b (ropeg) is a novel interferon-based therapy with favorable dosing schedules. A higher starting-dose (250 µg) regimen with simpler dose titrations was found to have a potent disease-modifying effect with respect to inducing a molecular response. PARADIGM-PV is a randomized, phase 4 study with the primary goal of assessing the efficacy of ropeg at this dosing regimen in alleviating Phl-dependence in both low- and high-risk patients with PV. The secondary endpoints include complete hematologic response, molecular response, symptom improvement, maintenance of median hematocrit (Hct) values < 45% without disease progression, and safety. Patients will be randomized equally to receive either ropeg every two weeks or to continue their current treatment with Phl or other cytoreductive agents (e.g., hydroxyurea, other interferons, or ruxolitinib) as applicable. All patients will receive Phl if their Hct values are elevated to ≥45% according to the National Comprehensive Cancer Network guidelines. The study will enroll approximately 70 patients internationally, including patients in the US. This study will provide new efficacy data, measured as the ability of ropeg to reduce Phl eligibility and modify the disease.

Prevalence, incidence, and thromboembolic events in polycythemia vera: a study based on longitudinal German health claims data

There is little evidence, particularly in Germany, on the epidemiology and the cytoreductive management of polycythemia vera (PV). We performed an observational study based on anonymized health claims data to provide estimates of the epidemiology of PV in Germany, to describe the use of cytoreductive drugs in patients with PV, and to assess the occurrence of thromboembolic events (TEs) in prevalent patients on continuous treatment with relevant cytoreductive drugs over time. For the year 2021, we estimated a PV prevalence of 28.6 per 100,000 and an incidence of 3.3 per 100,000 in the German adult population (≥ 18 years). We identified 83.2% of prevalent patients in 2021 as being at high risk for thromboembolic complications, based on age (≥ 60 years) and/or history of TEs. Contrary to treatment guidelines, 43.6% of these high-risk patients did not receive cytoreductive drug treatment in 2021. 63.5% of patients in 2021 who were treated with hydroxyurea (but not ruxolitinib) in that year, met our defined proxy criteria for intolerance/resistance to hydroxyurea. Over time, we observed a lower proportion of patients with TEs in patients continuously treated with ruxolitinib compared to patients treated with hydroxyurea who also met our defined proxy criteria for intolerance/resistance to hydroxyurea (35.8% vs. 56.3% after three years). Our findings suggest that currently available cytoreductive therapies are not being fully utilized according to treatment guidelines, which may lead to avoidable thromboembolic complications in this patient population.

Risk of bleeding in patients with essential thrombocythemia and extreme thrombocytosis

ABSTRACT

Approximately 25% of patients with essential thrombocythemia (ET) present with extreme thrombocytosis (ExT), defined as having a platelet count ≥1000 × 109/L. ExT patients may have an increased bleeding risk associated with acquired von Willebrand syndrome. We retrospectively analyzed the risk of bleeding and thrombosis in ExT vs non-ExT patients with ET at Dana-Farber Cancer Institute and Massachusetts General Hospital from 2014 to 2022 to inform treatment decisions. We abstracted the first major bleed, clinically relevant nonmajor bleed (CRNMB), and thrombotic events from medical records. We identified 128 ExT patients (28%) and 323 non-ExT patients (72%). Cumulative incidence of bleeding was not different in ExT vs non-ExT patients (21% vs 13% [P = .28] for major bleed; 16% vs 15% [P = .50] for CRNMB). Very low and low thrombotic risk ExT patients were more likely to be cytoreduced than very low- and low-risk non-ExT patients (69% vs 50% [P = .060] for very low risk; 83% vs 53% [P = .0059] for low risk). However, we found no differences in bleeding between ExT and non-ExT patients when restricting the risk of bleed from diagnosis to cytoreduction start date (28% vs 19% [P = .29] for major bleed; 24% vs 22% [P = .75] for CRNMB). Cumulative incidence of thrombosis was also not different between ExT and non-ExT patients (28% vs 25%; P = .98). This suggests that cytoreduction may not be necessary to reduce bleeding risk based only on a platelet count of 1 million. We identified novel risk factors for bleeding in patients with ET including diabetes mellitus and the DNMT3A mutation.

Novel approaches in myelofibrosis

Myelofibrosis (MF) is a clonal myeloid neoplasm characterized by bone marrow fibrosis, splenomegaly, and disease-associated symptoms, as well as increased mortality, due to thrombosis, severe bleeding, infections, or progression to acute leukemia. Currently, the management of MF patients is tailored according to risk scores, with higher-risk (intermediate-2 and high-risk) patients being assessed for allogeneic stem cell transplantation, which remains the only potentially curative treatment option. On the other hand, lower risk (low- and intermediate-1 risk) patients who are symptomatic may be treated with JAK inhibitors or other drugs. However, none of these drug treatments have induced relevant rates of durable complete remissions, and, therefore, novel treatments are needed to improve the long-term outcomes of MF patients. This review summarizes current preclinical and clinical approaches to MF therapy, including novel drug combinations involving JAK inhibitors and innovative monotherapies. These drugs target transcription, nuclear export, survival pathways, or various intracellular pathways, ranging from JAK-STAT signaling to PI3-Kinase, TP53, PIM1, or S100A8/A9/toll-like receptor pathways. Also, extracellular targeting using interferon, calreticulin mutant-specific antibodies, and other immunotherapeutic approaches are discussed, as well as various antifibrotic strategies. In addition, preclinical approaches that target individual mutated clones, for example, by mutation-specific JAK2V617F inhibitors or DNA repair pathway inhibitors, are presented. Finally, current efforts of generating novel endpoints for clinical trials aim more at disease modification and overall survival than at improvements of splenomegaly or symptoms. Together, the new generations of clinical trials promise to offer substantial improvements in the management of MF patients and long-term disease control.

Prognostic value of response to first-line hydroxyurea according to IPSET stratification in essential thrombocythemia

Hydroxyurea (HU) constitutes the first-line treatment in most patients with essential thrombocythemia (ET), but criteria for changing therapy are not clearly established. The prognostic value of complete hematological response (CHR) and resistance/intolerance to HU was assessed in 1080 patients from the Spanish Registry of ET, classified according to revised IPSET-Thrombosis stratification (Very low- n = 61, Low- n = 83, Intermediate- n = 261, and High-risk n = 675). With a median therapy duration of 5 years, CHR was registered in 720 (67%) patients (1-year probability 51%) and resistance/intolerance in 219 (20%) patients (5-years probability 13%). After correction by other risk factors, High-risk patients achieving CHR showed a reduced risk of arterial thrombosis (HR: 0.35, 95%CI: 0.2-0.6, p = 0.001) and a trend towards lower risk of venous thrombosis (HR: 0.45, 95%CI: 0.2-1.02, p = 0.06) whereas no association was observed for intermediate- or low-risk patients. In comparison with non-responders, intermediate- and high-risk patients achieving CHR had longer survival and lower myelofibrosis incidence. Development of resistance/intolerance to HU, mainly cytopenia, was associated with higher probability of myelofibrosis but no effect on survival or thrombotic risk was demonstrated. In conclusion, CHR with HU is associated with better outcomes and might be an early indicator for selecting candidates to second-line clinical trials.

Decision analysis for transplant candidates with primary myelofibrosis in the ruxolitinib era

The recent progress with ruxolitinib treatment might improve quality of life as well as overall survival in patients with primary myelofibrosis. Therefore, the optimal timing of allogeneic hematopoietic cell transplantation (HCT) in the ruxolitinib era remains to be elucidated. We constructed a Markov model to simulate the 5-year clinical course of transplant candidates with primary myelofibrosis and compared outcomes between those who underwent immediate HCT and those whose HCT was delayed until after ruxolitinib failure. Since older age was associated with an increased risk of mortality, we analyzed patients aged <60 and ≥60 years separately in subgroup analyses. Life expectancy was consistently longer in the groups undergoing delayed HCT after ruxolitinib failure regardless of the patients' age. Regarding quality-adjusted life years, a baseline analysis showed that immediate HCT was inferior to delayed HCT after ruxolitinib failure (2.19 vs. 2.26). In patients aged <60 years, immediate HCT was equivalent to delayed HCT after ruxolitinib failure (2.31 vs. 2.31). On the other hand, in patients aged ≥60 years, immediate HCT was inferior to delayed HCT after ruxolitinib failure (1.98 vs. 2.21). A one-way sensitivity analysis showed that the utility of being alive without chronic graft-versus-host disease after immediate HCT was the most influential parameter for quality-adjusted life years, and that a value higher than 0.836 could reverse the superiority of delayed HCT after ruxolitinib failure. As a result, delayed HCT after ruxolitinib failure is expected to be superior to immediate HCT, especially in patients aged ≥60 years, and is also a promising strategy even in those aged <60 years.

An unusual case report of myelofibrosis following treatment for acute promyelocytic leukemia with myeloid sarcoma as the initial manifestation

Introduction

Acute promyelocytic leukemia (APL) is a subtype of acute myeloid leukemia (AML), with myeloid sarcoma (MS) seldom occurring at onset. Myelofibrosis (MF) is a condition characterized by megakaryocytic proliferation and atypia with an array of clinical findings, but MF secondary to APL treatment is extremely rare. MF secondary occurring after treatment of APL with MS as the initial presentation has not been reported.

Case report

A 73-year-old male was admitted to our hospital in August 2016, presenting with a pain in his left shoulder, followed by right shoulder and bilateral hip pain. A progressive increase in a mass in the right sternoclavicular joint was also observed. After comprehensive examines, he was diagnosed as APL with MS as the initial manifestation in April 2017. The patient then underwent induction, consolidation, and maintenance therapies until August 2019 and achieved complete remission. However, twice examinations in December 2020 and September 2022 confirmed that MF was present.

Conclusion

This is the first case of MF secondary occurring after treatment of APL with MS. Early recognition of MS in APL patients is crucial for timely intervention and treatment initiation. Meticulous diagnostic work-up and careful monitoring during treatment are necessary to detect potential complications, which may significantly impact the patients' outcome. Also, a comprehensive management approach encompassing induction, consolidation, and maintenance therapies should be adopted to ensure optimal therapeutic responses and reduce the risk of recurrence or treatment-related complications.

Thrombosis in myeloproliferative neoplasms: a viewpoint on its impact on myelofibrosis, mortality, and solid tumors

This viewpoint summarizes findings from analyses of large personal patient databases of myeloproliferative neoplasms (MPNs) to assess the impact of thrombosis on mortality, disease progression, and second cancers (SC). Despite advances, the current incidence of arterial and venous thrombosis remains a challenge. These events appear to signal a more aggressive disease course, as evidenced by their association with myelofibrosis progression and mortality using multistate models and time-dependent multivariable analysis. Inflammatory biomarkers, such as the neutrophil-to-lymphocyte ratio (NLR), are associated with the aggressiveness of polycythemia vera (PV) and essential thrombocythemia (ET), linking thrombosis to SC risk. This suggests a common inflammatory pathway likely influencing cardiovascular disease and cancer incidence. Notably, this is observed more frequently in younger patients, likely due to prolonged exposure to MPN and environmental inflammatory triggers. These data underscore the need for new studies to validate these associations, delineate the sequence of events, and identify therapeutic targets to mitigate thrombotic events and potentially improve overall patient outcomes in MPN.

Combination therapy with ruxolitinib and pegylated interferon alfa-2a in newly diagnosed patients with polycythemia vera

ABSTRACT

We report the 2-year end-of-study results from the phase 2 COMBI II clinical trial investigating the combination treatment of ruxolitinib and low-dose pegylated interferon alfa-2a in patients with newly diagnosed polycythemia vera (PV). The primary outcome was safety and key secondary endpoints were efficacy, based on hematologic parameters, quality-of-life measurements, and JAK2V617F variant allele frequency (VAF). We used the 2013 European LeukemiaNet and International Working Group-Myeloproliferative Neoplasms Research remission criteria. The remission criteria included remissions in symptoms, splenomegaly, peripheral blood counts, and bone marrow. We included 25 patients with PV with a median age of 70 years; 5 of those had prior thromboembolic events and 3 had computed tomography-verified splenomegaly. Two patients stopped both study drugs; 1 of these due to progression to post-PV myelofibrosis, the only one with a grade 3 infection. No events of herpes zoster infections were observed. None of the patients discontinued treatment due to psychiatric symptoms. The peripheral blood cell count remission rate was 92% at 24 months. Using the 2013 European LeukemiaNet and International Working Group-Myeloproliferative Neoplasms Research remission criteria, 14 (56%) achieved remission at 24 months; 3 (12%) achieved complete remission and 11 (44%) achieved partial remission. The following items from the Myeloproliferative Neoplasm Symptom Total Symptom Score were significantly reduced: abdominal discomfort, night sweats, itching, and bone pain. The median JAK2V617F VAF decreased from 47% (95% confidence interval [CI], 35-59) to 7% (95% CI, 3-15), and 60% of patients achieved molecular remission. In conclusion, combination treatment improved cell counts; bone marrow cellularity, and fibrosis; and decreased JAK2V617F VAF; with acceptable toxicity in patients with PV. The trial was registered at www.clinicaltrialsregister.eu as #EudraCT2018-004150-13.

Absence of canonical mutations in pediatric essential thrombocytosis: a case series

Essential thrombocytosis (ET) is a rare myeloproliferative disease in children, and there are few standard management guidelines. We herein report a case series of 10 pediatric patients with ET diagnosed at our institution over a period of 13 years. All patients fulfilled the World Health Organization diagnostic criteria for ET, and none harbored the canonical ET mutations JAK2 V617F, CALR, or MPL. Overall, 7 of the 10 patients received treatment for ET, and during follow-up, 3 of these 7 patients discontinued cytoreductive therapy. No patient experienced hemorrhagic or thrombotic complications. Our case series emphasizes that the genetic features of pediatric ET may differ significantly from those of adult ET, and that treatment cessation is a possibility for some patients.

Bibliometric analysis of worldwide research on Polycythemia Vera in the 21st century

Polycythemia vera (PV) is a myeloproliferative tumor with low incidence and complex symptoms, affecting patients' quality of life and shortening their life span. Since the beginning of the 21st century, there has been an update but a need for uniform consensus regarding diagnosing and treating PV. With the continued interest of researchers in this field, a bibliometric study of PV is necessary. This paper aims to analyze articles on PV through bibliometric software to provide collaborative information and new ideas for researchers in this field. We collected PV-related publications in the Web of Science Core Collection database from 2000 to 2023. The included literature was analyzed using Citespace (6.2.R2), VOSviewer (1.6.19), and Bibliometrix. The study included country/region, institution, authors, journals, keywords, and references, and a visual knowledge network diagram was constructed. Microsoft Excel 2013 was also used for statistical analysis. A total of 1,093 articles were eventually included. The number of PV-related publications has steadily increased from 2000 to the present, with great potential for future growth. The US and US institutions have contributed more to this field, with the US ranking first in the number of publications, total citations, and centrality. Alessandro M. Vannucchi is the most published author. Tefferi, Ayalew is the most cited author. And BLOOD has the most publications, topping the list of the eleven high-productivity core source journals. The most cited article was "Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders" (Baxter, EJ, 2005). By examining the keywords, we found that the diagnosis and typing of true erythrocytosis, the use of ruxolitinib, and the tyrosine kinase JAK2 are the research hotspots in the field; genetic and molecular research in the field of true erythrocytosis is a cutting-edge topic in the field; and risk factors for true erythrocytosis is a cutting-edge hotspot issue in the field. The fruitful research in this century has laid the foundation for developing the field of PV. The information in this article will provide researchers with current hotspots and future potential in the discipline, helping the field achieve more extraordinary breakthroughs. Currently, research should focus on increasing global multicenter collaborative research in diagnosis and treatment to develop scientifically recognized diagnostic and treatment protocols and new clinical drug research. Our proposed model of global innovation collaboration will provide strong support for future research.

The role of corticosteroids in the current treatment paradigm for myelofibrosis

INTRODUCTION

Myelofibrosis (MF) is a clonal hematological disorder characterized by bone marrow fibrosis, splenomegaly, and inflammatory cytokine dysregulation. While the role of steroids in MF is not fully defined, their anti-inflammatory properties may offer therapeutic benefits, particularly in managing anemia and other cytopenias. Steroids exert their effects by suppressing pro-inflammatory cytokines such as IL1, IL6, and TNF, and by enhancing anti-inflammatory cytokines like IL4 and IL10. Elevated levels of IL6 and other cytokines in MF are associated with anemia and poor prognosis, suggesting that steroid therapy could mitigate these effects.

AREAS COVERED

In this manuscript, we review clinical studies which evaluated the safety and efficacy of steroids in MF patients. Moreover, we examine clinical data of the combination of steroids with immunomodulatory agents and JAK inhibitors. Our literature search consisted of an extensive review of PubMed and clinicaltrials.gov.

EXPERT OPINION

The role of steroids in the management of MF remains poorly defined, though emerging evidence suggests a potential therapeutic benefit, particularly in managing anemia and other cytopenias. The combination with IMIDs has also yielded positive outcomes as demonstrated in several studies. Steroids may also play a crucial role in managing cytopenias in MF patients receiving JAKi.

A Case of Renal Artery Thrombosis With Concurrent Adrenal Hemorrhage in Polycythemia Vera

Polycythemia vera (PV) is a rare myeloproliferative neoplasm characterized by the clonal proliferation of hematopoietic stem cells, leading to an elevated red blood cell mass. This hyperproliferative state increases blood viscosity and predisposes patients to thrombotic events, which are a significant cause of morbidity and mortality in PV. The diagnosis of PV is typically confirmed through elevated hemoglobin or hematocrit levels, low serum erythropoietin, and the presence of the Janus kinase 2 (JAK2) mutation. Common complications include venous and arterial thromboses, hemorrhage, and transformation to myelofibrosis or acute leukemia. A 68-year-old female with a history of PV and chronic kidney disease (CKD) presented with uremic symptoms in the form of malaise and nausea. Laboratory investigations indicated acute kidney injury (AKI) and hyperkalemia. Imaging evaluation of renal US Doppler revealed renal artery thrombosis and an incidental adrenal hemorrhage. The patient was managed with intravenous heparin and did not receive thrombolytics or thrombectomy. Her renal function did not improve, necessitating the initiation of hemodialysis (HD) during hospitalization. Over the course of the next few weeks, her renal parameters improved and she managed to be discharged from dialysis. The primary goal of this study was to highlight a rare presentation of renal artery thrombosis secondary to polycythemia vera (PV) and discuss the complexities involved in managing the underlying disease and its thrombotic complication, particularly in the presence of concomitant bleeding. Effective management of PV-related thrombosis requires a delicate balance between anticoagulation to prevent further thrombotic events while carefully addressing the risk of hemorrhage.

Predictive significance of high neutrophil ratio for thrombosis in myeloproliferative neoplasms: JSH-MPN-R18 subanalysis

Thrombosis in myeloproliferative neoplasms (MPNs) is an important clinical problem, and risk-stratified management is essential. To identify the clinical characteristics of thrombosis in patients with MPNs, a nationwide multi-institutional retrospective analysis (JSH-MPN-R18) was conducted. The aim of the present study was to perform a sub-analysis of JSH-MPN-R18 findings to clarify the predictive parameters for thrombosis among complete blood count (CBC) results. Among the patients enrolled in JSH-MPN-R18, those with essential thrombocythemia (ET; n = 1152) and polycythemia vera (PV; n = 456) were investigated. We analyzed and compared CBC parameters between patients with and those without any thrombotic events using Welch's T-test. Statistical analyses were performed using the R statistical software. Thrombotic events were observed in 74 patients with ET. In multivariate analysis, only the neutrophil ratio was slightly but significantly higher for ET patients with thrombosis than for those without (p < 0.05). Of note, the absolute neutrophil count (aNeu) was considered a useful predictive tool for thrombosis among patients classified as low-risk according to the revised International Prognostic Score of Thrombosis for Essential Thrombocythemia. Among PV patients, those with thrombosis showed significantly higher hematocrit and aNeu than did those without thrombosis. As a thrombosis-associated factor, the neutrophil ratio was slightly but significantly elevated in patients with ET. This myeloid skew might reflect a higher value of JAK2 V617F allelic frequency in patients with ET with thrombosis; this was not clarified in JSH-MPN-R18. Further accumulation of evidence, including genetic information for JAK2 and other passenger mutations, is warranted.

Liver and spleen shear-wave elastography in the diagnosis and severity staging of myeloproliferative diseases and myelofibrosis

AIMS

Spleen and liver stiffness, investigated by VCTE (Vibration-Controlled Transient Elastography), have been associated with marrow fibrosis in patients with myeloproliferative neoplasms (MPNs). Tissue stiffness can be assessed by shear wave point (pSWE) and bidimensional elastography (2DSWE). Spleen stiffness (SS) values were higher in Myelofibrosis (MF) and Polycythemia Vera (PV) compared to Essential Thrombocythemia (ET). We aimed to identify SWE differences between MPN patients and healthy volunteers; to evaluate specific SWE features in patients with MF, PV and ET; to establish a correlation with bone marrow fibrosis in patients with myeloproliferative disease.

METHODS

Patients with myeloproliferative disease and healthy volunteers performed evaluation of spleen and liver stiffness (LS) by pSWE and 2DSWE.

RESULTS

A total of 218 subjects were included: 143 with myeloproliferative disease (64 MF, 29.4%, 33 PV, 15.1% and 46 ET, 21.1%), and 75 (34.4%) healthy volunteers. Compared to volunteers, MF patients had greater spleen (pSWE 40.9 vs. 26.3 kPa, p < 0.001; 2DSWE 34.9 vs. 20.1 kPa, p < 0.001), and liver stiffness (pSWE 7.72 vs. 5.52 kPa, p < 0.001; 2DSWE 6.96 vs. 5.01 kPa, p < 0.001). In low (0-1) (n = 81, 60.4%) versus high-grade bone marrow fibrosis (2-3) (n = 42, 39.6%), is evident a higher median stiffness in patients with higher grades of fibrosis both for liver (pSWE 5.2 vs. 6.65 kPa; 2DSWE 5.1 vs. 6.05 kPa) and spleen (pSWE 27.2 vs. 37.9 kPa, 2DSWE 21.7 vs 30.75 kPa-p < 0.001 in both).

CONCLUSION

SWE evaluation distinguishes MF patients from HV and ET/PV and may help in MPN diagnosis. LS and SS values are associated with bone marrow fibrosis grade.

Impact of Phlebotomy on Quality of Life in Low-Risk Polycythemia Vera

Polycythemia vera is an indolent myeloproliferative disorder that predisposes patients to venous and arterial thrombosis and can transform into myelofibrosis and acute myeloid leukemia. Consistent phlebotomy prevents life-threatening cerebrovascular and coronary artery disease and prolongs survival in low-risk polycythemia vera (patients under 60 years without thrombosis). However, despite its effectiveness in preventing serious complications, phlebotomy does not necessarily enhance the quality of life (QoL). This review assesses QoL issues associated with low-risk PV, explores alternative management strategies such as erythrocytapheresis, and discusses the roles of hydroxyurea, peginterferon, ruxolitinib, and other novel agents in potentially improving disease management and patient outcomes.

Clinical impact of mutated JAK2 allele burden reduction in polycythemia vera and essential thrombocythemia

The variant allele frequency (VAF) of driver mutations (JAK2, CALR) in myeloproliferative neoplasms is associated with features of advanced disease and complications. Ruxolitinib and interferon were reported to variably reduce the mutant VAF, but the long-term impact of molecular responses (MR) remains debated. We prospectively measured changes in JAK2 and CALR VAF in 77 patients with polycythemia vera and essential thrombocythemia, treated with ruxolitinib for a median of 8 years, and assessed correlation with complete clinical and hematological response (CCHR) and outcomes. At last observation time, JAK2 VAF reduced overall from a median of 68% (range, 20%-99%) to 3.5% (0%-98%). A profound and durable MR (DMR; defined as a VAF stably ≤2%), including complete MR in 8%, was achieved in 20% of the patients, a partial MR (PMR; VAF reduction >50% of the baseline level) in 25%, and 56% had no molecular response (NMR). A CCHR was reached by 69% overall, independently of any degree of MR achieved; conversely, a DMR correlated with longer duration of CCHR and, most importantly, with reduced rate of progression to myelofibrosis and with longer myelofibrosis-free, event-free and progression-free survival. Achievement of PMR also had some favorable impact on outcomes, compared to NMR. A baseline JAK2 VAF <50%, and a VAF reduction of ≥35% after 2 years of treatment, predicted for the achievement of DMR and reduced progression to myelofibrosis. Overall, these findings support the clinical value of achieving profound, durable MR and its consideration as surrogate endpoint in future clinical trials.

The evolving landscape of polycythemia vera therapies

INTRODUCTION

The treatment landscape of polycythemia vera (PV) has seen major advancements within the last decade including approval of ruxolitinib in the second line setting after hydroxyurea, ropegylated interferon-α2b, and advanced clinical development of a novel class of agents called hepcidin mimetics.

AREAS COVERED

We provide a comprehensive review of the evidence discussing the risk stratification, treatment indications, role and limitations of phlebotomy only approach and pivotal trials covering nuances related to the use of interferon-α (IFN-α), ruxolitinib, hepcidin mimetics, and upcoming investigational agents including HDAC and LSD1 inhibitors.

EXPERT OPINION

The research paradigm in PV is slowly shifting from the sole focus on hematocrit control and moving toward disease modification. The discovery of hepcidin mimetics has come as a breakthrough in restoring iron homeostasis, achieving phlebotomy-independence and may lead to improved thrombosis-free survival with stricter hematocrit control. On the other hand, emerging data with IFN- α and ruxolitinib as well as combination of the two agents suggests the potential for achieving molecular remission in a subset of PV patients and long-term follow-up is awaited to validate the correlation of molecular responses with clinically relevant outcomes of progression-free and thrombosis-free survival.

Long-term pharmacodynamic and clinical effects of twice- versus once-daily low-dose aspirin in essential thrombocythemia: The ARES trial

Patients with essential thrombocythemia (ET) are treated with once-daily low-dose aspirin to prevent thrombosis, but their accelerated platelet turnover shortens the antiplatelet effect. The short-term Aspirin Regimens in EsSential Thrombocythemia trial showed that twice-daily aspirin dosing restores persistent platelet thromboxane (TX) inhibition. However, the long-term pharmacodynamic efficacy, safety and tolerability of twice-daily aspirin remain untested. We performed a multicenter, randomized, open-label, blinded-endpoint, phase-2 trial in which 242 patients with ET were randomized to 100 mg aspirin twice- or once-daily and followed for 20 months. The primary endpoint was the persistence of low serum TXB2, a surrogate biomarker of antithrombotic efficacy. Secondary endpoints were major and clinically relevant non-major bleedings, serious vascular events, symptom burden assessed by validated questionnaires, and in vivo platelet activation. Serum TXB2 was consistently lower in the twice-daily versus once-daily regimen on 10 study visits over 20 months: median 3.9 ng/mL versus 19.2 ng/mL, respectively; p < .001; 80% median reduction; 95% CI, 74%-85%. No major bleeding occurred. Clinically relevant non-major bleedings were non-significantly higher (6.6% vs. 1.7%), and major thromboses lower (0.8% vs. 2.5%) in the twice-daily versus once-daily group. Patients on the twice-daily regimen had significantly lower frequencies of disease-specific symptoms and severe hand and foot microvascular pain. Upper gastrointestinal pain was comparable in the two arms. In vivo platelet activation was significantly reduced by the twice-daily regimen. In patients with ET, twice-daily was persistently superior to once-daily low-dose aspirin in suppressing thromboxane biosynthesis and reducing symptom burden, with no detectable excess of bleeding and gastrointestinal discomfort.

Hematocrit control and thrombotic risk in patients with polycythemia vera treated with ruxolitinib in clinical practice

Polycythemia vera (PV) is a myeloproliferative neoplasm characterized by unregulated red blood cell production resulting in elevated hemoglobin and/or hematocrit levels. Patients often have symptoms such as fatigue, pruritus, and painful splenomegaly, but are also at risk of thrombosis, both venous and arterial. Ruxolitinib, a selective Janus kinase inhibitor, is approved by the US Food and Drug Administration as second-line cytoreductive treatment after intolerance or inadequate response to hydroxyurea. Although ruxolitinib has been widely used in this setting, limited data exist in the literature on ruxolitinib treatment patterns and outcomes among patients with PV in routine clinical practice. We report a retrospective, observational, cohort study of patients treated for PV with ruxolitinib across three US centers (academic and regional practice) from December 2014-December 2019. The study included 69 patients, with a median follow-up duration of 3.7 years (95% CI, 2.9-4.4). Our data demonstrate very high rates of hematocrit control (88% of patients by three months and 89% by six months); few patients required dose adjustments or suspension. No arterial thromboses were observed; however, the follow-up duration does not allow for the generation of meaningful conclusions from this. Three patients had thrombotic events; one was in the setting of a second malignancy, one post-operative, and a third related to prolonged immobility. We also found that 28% of patients initiated ruxolitinib as a result of poorly controlled platelet counts, second only to hydroxyurea intolerance (46%) as a reason to start therapy. In clinical practice, ruxolitinib continues to be effective in controlling hematocrit levels after three and six months of treatment in patients and is associated with low thrombotic risk.

Systemic Inflammatory Index in Polycythemia Vera and Its Prognostic Implications

Background: This study aimed to evaluate the clinical and prognostic associations of the systemic inflammatory index (SII) in polycythemia vera (PV) patients. SII integrates information on absolute neutrophil (ANC), lymphocyte (ALC), and platelet counts into one index (calculated as ANCxALC/platelet count) and was previously shown to predict thrombotic and mortality risks in the general population. Methods: A total of 279 PV patients treated in several hematologic centers in Croatia and Serbia was retrospectively evaluated. Results: The median SII for the overall cohort was 1960. Higher SII stratified at the specific cut-off points was significantly associated with shorter time to thrombosis (TTT; p = 0.004) driven by arterial thrombotic events, and shorter overall survival (OS; p < 0.001). Higher SII was able to refine the European Leukemia Net-defined high-risk patient subgroup for both thrombotic and survival risks, especially in individuals over 60 years of age. SII and all other evaluated CBC components and indices (leukocytes, ANC, ALC, platelets, neutrophil to lymphocyte ratio (NLR), and platelet to lymphocyte ratio (PLR)) demonstrated low-to-modest prognostic properties, whereas SII outperformed other parameters with respect to TTT and OS prognostications. Discussion: The presented results complement prior studies evaluating the prognostic performance of different CBC components for thrombotic and survival risk predictions and offer more options to personalize PV treatments.

Epidemiology and disease characteristics of myelofibrosis: a comparative analysis between Italy and global perspectives

Myelofibrosis (MF) is a clonal disorder of hematopoietic stem cells characterized by altered bone marrow function and fibrosis. The aim of this narrative review is to report on the most recent epidemiologic data and to discuss features of MF and current strategies for the management of this condition in clinical practice. MF features covered by our review will include: characteristics of patients with MF; myeloproliferative and myelodepletive phenotypes; MF-associated thrombosis and bleeding; risk of infections; prefibrotic and overt PMF; secondary MF. Finally, we will discuss a few aspects of MF management in clinical practice and suggest strategies for its optimization and standardization. The focus of our paper is on Italy, but relevant data from other countries will also be reviewed.

Antithrombotic Therapy in Cancer Patients with Cardiovascular Diseases: Daily Practice Recommendations by the Hemostasis Working Party of the German Society of Hematology and Medical Oncology (DGHO) and the Society for Thrombosis and Hemostasis Research (GTH e.V.)

Active cancer by itself but also chemotherapy is associated with an increased risk of cardiovascular disease (CVD) and especially coronary artery disease (CAD) and atrial fibrillation (AF). The frequency of CVD, CAD, and AF varies depending on comorbidities (particularly in older patients), cancer type, and stage, as well as the anticancer therapeutic being taken. Many reports exist for anticancer drugs being associated with CVD, CAD, and AF, but robust data are often lacking. Because of this, each patient needs an individual structured approach concerning thromboembolic and bleeding risk, drug-drug interactions, as well as patient preferences to evaluate the need for anticoagulation therapy and targeting optimal symptom control. Interruption of specific cancer therapy should be avoided to reduce the potential risk of cancer progression. Nevertheless, additional factors like thrombocytopenia and anticoagulation in the elderly and frail patient with cancer cause additional challenges which need to be addressed in daily clinical management. Therefore, the aim of these recommendations is to summarize the available scientific data on antithrombotic therapy (both antiplatelet and anticoagulant therapy) in cancer patients with CVD and in cases of missing data providing guidance for optimal careful decision-making in daily routine.

DNMT3A/TET2/ASXL1 Mutations are an Age-independent Thrombotic Risk Factor in Polycythemia Vera Patients: An Observational Study

BACKGROUND

 Polycythemia vera (PV) patients are classified as high or low thrombotic risk based on age and prior history of thrombosis. Despite adherence to treatment recommendations, vascular events remain frequent, leading us to question whether thrombotic risk stratification could be improved. We previously reported an association between thrombotic events and mutations in DTA genes (DNMT3A, TET2, and ASXL1). The objective of this study was to confirm this observation in a larger series of PV patients.

METHODS

 PV patients with a minimum follow-up of 3 years were recruited from 8 European centers. Medical history was searched for thrombotic event recorded at any time and next-generation sequencing carried out with a myeloid panel. Multivariable logistic regression evaluated the impact of variables on thrombotic risk. Kaplan-Meier thrombosis-free survival curves were compared by the log rank test. Associations in the total cohort were confirmed in a case-control study to exclude selection bias.

RESULTS

 Of the 136 patients recruited, 74 (56.1%) had a thrombotic event, with an incidence density of 2.83/100 person-years. In multivariable analysis, DTA mutation was a risk factor for thrombotic event, being predictive for shorter thrombosis-free survival in the whole cohort (p = 0.007), as well as in low-risk patients (p = 0.039) and older patients (p = 0.009), but not for patients with a prediagnostic event. A gender- and age-matched case-control study confirmed the increased risk of thrombotic event for PV patients with a DTA mutation.

CONCLUSION

 Our results support the use of molecular testing at diagnosis to help predict which PV patients are at higher risk of developing thrombosis.

Impact of Hydroxyurea to Treat Haematological Disorders on Male Fertility: Two Case Reports and a Systematic Review

PURPOSE

Hydroxyurea (HU) is a cytoreductive agent used as standard treatment option for sickle cell anaemia/disease (SCD), essential thrombocythemia (ET), and polycythaemia vera (PV). Despite its overall good safety profile, its use also in relatively young patients raises an interest on its potential impact on spermatogenesis. To perform a systematic review of all published articles investigating fertility in male patients affected by SCD, ET, and PV and treated with HU. Two paradigmatic case reports of patients affected by PV and ET, respectively, have been also reported.

MATERIALS AND METHODS

PubMed, EMBASE, and Cochrane databases were queried for all the published studies indexed up to November 15th, 2022. A combination of the following keywords was used: "hydroxyurea," "fertility," "male," "sperm," "sickle cell anaemia," "sickle cell disease," "essential thrombocythemia," "polycythaemia vera."

RESULTS

Of 48 articles identified, 8 studies, involving 161 patients, were eligible for inclusion. Overall, the number of spermatogonia per round cross section of seminiferous tubule were decreased in patients with SCD compared to healthy males. HU treatment was always associated with a worsening of semen parameters, even up to azoospermia. Notably, treatment discontinuation was associated with an improvement of semen parameters and a trend toward normalization in the case of PV and ET, with a less clear amelioration in men with SCD. In both our patients with either PV or ET, HU discontinuation was associated with a significant improvement of spermatogenesis with successful spontaneous pregnancies.

CONCLUSIONS

Published evidence do not consistently report normalization of spermatogenesis after HU discontinuation in SCD cases. Conversely, the literature almost consistently reported an improvement of semen parameters at the discontinuation of HU therapy in PV and ET cases. Our real-life two cases confirmed those findings. The willing of fatherhood and the need for effective fertility treatment warrant further research to improve work-up management in men with hematological disorders.

Myeloproliferative neoplasms in the adolescent and young adult population: A comprehensive review of the literature

Myeloproliferative neoplasms (MPN) are characterized by a clonal proliferation of myeloid lineage cells within the bone marrow. The classical BCR-ABL negative MPNs are comprised of polycythaemia vera, essential thrombocythaemia and primary myelofibrosis. Historically, the majority of MPNs are diagnosed in adults older than 60 years of age; however, in recent years, there has been recognition of MPNs in the adolescent and young adult (AYA) population. AYAs with MPN, typically defined as between the ages of 15 and 39 years old, may comprise up to 20% of patients diagnosed with MPN. They demonstrate unique patterns of driver mutations and thrombotic events and remain at risk for progression to more aggressive disease states. Given the likely long length of time they will live with their disease, there is a significant unmet need in identifying well-tolerated and effective treatment options for these patients, particularly with the advent of disease modification. In this review, we provide a comprehensive overview of the clinical features, disease course and management of AYA patients with MPN and, in doing so, highlight key characteristics that distinguish them from their older counterparts.

SOHO State of the Art Updates and Next Questions | Diagnosis, Outcomes, and Management of Prefibrotic Myelofibrosis

Prefibrotic primary myelofibrosis (prefibrotic PMF) is a myeloproliferative neoplasm with distinct characteristics comprising histopathological and clinico-biological parameters. It is classified as a subtype of primary myelofibrosis. In clinical practice, it is essential to correctly distinguish prefibrotic PMF from essential thrombocythemia especially but also overt PMF besides other myeloid neoplasms. Risk stratification and survival outcomes for prefibrotic PMF are worse than that of ET but better than that of overt PMF. Rates of progression to overt PMF and blast phase disease are also higher for prefibrotic PMF than ET. In this review we first discuss the historical context to the evolution of prefibrotic PMF as an entity, its presenting features and diagnostic criteria. We emphasize the differences between prefibrotic PMF, ET, and overt PMF with regards to presenting features and disease outcomes including thrombohemorrhagic events and progression to fibrotic and blast phase disease. Next, we discuss the risk stratification models and contextualize these in the setting of clinical management. We share our view of personalizing treatment to address unique patient needs in the context of currently available management options. Lastly, we discuss areas of critical need in clinical research and speculate on the possibility of future disease course modifying therapies in prefibrotic PMF.