Thrombosis Linked With Second Cancer Risk in MPNs

Among patients with myeloproliferative neoplasms (MPNs), arterial thrombosis incidence appears to raise the risk of second cancers (SCs) and consequently, mortality, according to an analysis published in Blood Cancer Journal. Inflammatory biomarkers in these diseases suggest a more aggressive disease etiology, the authors added.

In the case of polycythemia vera (PV) or essential thrombocythemia (ET), previous research suggested that thrombosis may heighten the risk of progression to secondary myelofibrosis, which has a high mortality rate. For this retrospective analysis of MPN-patient data, researchers aimed to determine the elements of thrombosis that promote this risk.

Overall, data were evaluated from 1545 patients with PV, 891 patients with ET, 180 patients who were pre-primary myelofibrosis (PMF), and 707 patients with PMF. The median follow-up periods in the PV, ET, pre-PMF, and PMF groups were 5.6 months, 5.6 months, 6.1 months, and 2.92 months, respectively; 19%, 12%, 15%, and 7% of patients had a thrombosis event.

Future therapies should focus on targeting the complex mechanisms involved in both atherogenesis and thrombogenesis…and anti-inflammatory drugs for primary and secondary prevention of thrombosis.

Analysis of the patient data showed that arterial, but not venous or splanchnic, thrombosis was linked with a greater risk of SCs (odds ratio [OR], 2.53; 95% CI, 2.4-5.17). A white blood cell count of at least 11 x 109/L appeared to trend toward a greater risk of SCs, but this link was not significant (OR, 1.27; 95% CI, 0.96-1.67); this was also true of a PMF vs ET diagnosis (OR, 2.54; 95% CI, 0.97-6.61).

“Future therapies should focus on targeting the complex mechanisms involved in both atherogenesis and thrombogenesis, including new cytoreductive drugs targeting the somatic mutations, such as interferon and JAK2 inhibitors, and anti-inflammatory drugs for primary and secondary prevention of thrombosis,” the authors wrote in their report.

Disclosures: This research was supported by FROM-Fondazione per la Ricerca Ospedale di Bergamo-ETS.

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Thrombosis and Inflammation Drive Mortality and Cancer Risk in Myeloproliferative Disorders

November 15, 2024

Lisa Kuhns, PhD, MD

Despite the advancements in treatment, thrombosis remains a significant challenge for patients with myeloproliferative neoplasms (MPNs), contributing to increased mortality and the development of secondary cancers, according to an article published in Blood Cancer Journal.

“These risks arise from disease-related clonal hematopoiesis and subsequent chronic systemic inflammation, leading to thrombosis and genetic instability,” explained Tiziano Barbui, FROM, Fondazione per la Ricerca Ospedale di Bergamo ETS, Bergamo, Italy, and coauthors. “In our large databases of patients with MPN, we investigated the incidence and risk factors of thrombosis that may explain this association, culminating in an increased risk of mortality.”

Recent research has highlighted the persistent risk of thrombotic events in patients with classic MPNs, including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). These disorders are characterized by a high incidence of both arterial and venous thrombosis, which complicates patient management and contributes to disease progression. Notably, studies indicate that approximately 20% of MPN diagnoses are heralded by thrombotic events, with ongoing risks observed over time.

A large-scale study involving more than 9000 patients with MPN revealed significantly elevated hazard ratios for thrombotic events compared with matched controls. Specifically, arterial thrombosis hazard ratios were 3.0 at 3 months and 2.0 at 1 year postdiagnosis. Venous thrombosis rates were even more alarming, with hazard ratios of 9.7 at 3 months and 4.7 at 1 year. While conventional treatments such as hydroxyurea have demonstrated efficacy in reducing arterial thrombosis, their impact on venous events is less pronounced.

The implications of these findings extend beyond immediate health risks and suggest a potential link between thrombosis and progression to more severe forms of MPNs, such as myelofibrosis and acute leukemia. In particular, arterial thrombosis has been identified as an independent predictor of increased mortality in patients with ET and PV. For instance, a multistate model analysis indicated that patients experiencing arterial thrombosis had a 25% increase in mortality risk compared with those without such events.

Emerging evidence also suggests that thrombosis may be associated with an increased risk of developing secondary cancers in patients with MPN. A nested case-control study found that the occurrence of arterial thrombosis was independently linked to a higher incidence of secondary cancers, particularly among younger patients with MPNs. This correlation underscores the complex interplay between chronic inflammation induced by MPNs and the risk factors for both cardiovascular disease and cancer.

“We believe that arterial, and possibly venous thrombosis occurring during follow-up should be considered in the context of long-term occurring outcomes, including an increased incidence of solid tumors,” concluded the study authors.

Continued research is essential to unravel the underlying mechanisms linking thrombosis with disease progression and secondary malignancies, ultimately improving patient outcomes in this vulnerable population.

Reference

Barbui T, Ghirardi A, Carobbio A, et al. Thrombosis in myeloproliferative neoplasms: a viewpoint on its impact on myelofibrosis, mortality, and solid tumors. Blood Cancer J. 2024;14(1):188. doi:10.1038/s41408-024-01169-6

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Studies Highlight Prognostic Value of Neutrophil-to-Lymphocyte Ratio in MPNs

November 14, 2024

Author(s): Mary Caffrey

Two studies published this month are pointing to the value of the neutrophil-to-lymphocyte ratio (NLR) in forecasting either thrombosis or mortality risk in different myeloproliferative neoplasms (MPNs).1,2

Neutrophil | Image: Blausen Medical 2014

This inflammatory biomarker has emerged as an indicator due to the behavior of neutrophils in MPNs; they are known to produce cytokines when activated and to interact with tissue macrophages and dendritic cells, according to authors of a November 6, 2024, study in Blood Cancer Journal that explored NLR as a prognostic indicator of mortality in polycythemia vera (PV).1

These authors, from several institutions in Italy, analyzed the NLR in 1508 patients with PV and concluded that those with an NLR of at least 5 “were generally older, had a longer disease history, and had higher cardiovascular risk factors, more arterial thrombosis, and more aggressive blood counts, indicating a more proliferative disease.”

This was a prospective study based on patients enrolled in the European Collaboration on Low-Dose Aspirin in Polycythemia Vera (ECLAP) trial, a randomized study to assess the risk/benefit ratio of low-dose aspirin in PV.3

The authors of the new study analyzed data from the 151 deaths (10%) that occurred among the study population, and found an inverse relationship between lymphocyte counts and mortality risk, while also finding that higher lymphocyte counts were associated with a lower risk of death. Their data indicated that a higher NLR correlated with an increased risk of death.1

Thus, these authors concluded that NLR was an accurate predictor of mortality, and those patients with a ratio of at least 5 had worse overall survival with twice the mortality rate of those with a ratio less than 5.1

Previous venous thrombosis was also a strong predictor of death, they wrote.

Findings in Cancer. These findings were consistent with results published November 12, 2024, in Cancer, the official journal of the American Cancer Society, which found a relationship between NLR value at diagnosis and a risk of thrombotic events later on.Although this second study was a retrospective study involving fewer patients (473) with essential thrombocythemia (ET), the results also found a predictive value for NLR.

Authors in Cancer, from the University of Milan, reported a total of 78 thrombotic events among the 473 patients, for an incidence rate of 1.8 events per 100 patients/year. This analysis found that an NLR value of at least 4 at diagnosis was associated with a higher cumulative thrombotic risk (HR, 2.05; 95% CI, 1.29-2.28; P = .0001), as well as having diabetes and hypertension.2

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Frequent Testing for Driver Mutations Critical in Myelofibrosis

Nov 12, 2024

Researchers from the Munich Leukemia Laboratory in Germany have developed a model that uses 12 genetic markers to accurately stratify patients with myeloproliferative neoplasms (MPNs), according to a study published online ahead of print in Leukemia.

The WHO categorizes classical MPNs—using cytomorphology, bone marrow biopsy, grading of fibrosis, blood counts, and a handful of molecular markers—into four individual entities: chronic myeloid leukemia (CML) and the BCR::ABL1 negative MPNs polycythemia vera (PV), primary myelofibrosis (PMF), and essential thrombocythemia (ET).

“However, overlaps, borderline findings, or transitions between MPN subtypes occur, and incomplete clinical data often complicates diagnosis,” Manja Meggendorfer, PhD, and the study coauthors wrote.

The researchers analyzed 355 patients with MPN to use the results to stratify MPN entities and provide prognostic information. The investigation revealed the presence of genetically distinct subgroups with different cytogenetic abnormalities, mutations, and JAK2 allele statuses.

“Notably, differences in JAK2 allele status (heterozygous/homozygous) correlated with diverse EFS [event-free survival] and OS [overall survival] outcomes, potentially due to additional prognostic mutations,” the researchers reported. “In contrast, groups with cytogenetic aberrations and additional mutations generally had shorter EFS and poorer OS regardless of the diagnosed entity, aligning with studies on the impact of karyotype and mutation count on survival.”

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JAK2 Mutations Rarely Found in Patients With MPN Living in High Altitude Areas Who Have Unprovoked Thrombotic Events

JAK2 mutations are rarely found in patients with a myeloproliferative neoplasm (MPN) who have unprovoked thrombotic events — deep vein thrombosis (DVT), pulmonary embolism (PE), or atypical thrombosis — living in high-altitude regions, according to a study published in the International Journal of General Medicine. 

Thrombosis often serves as the initial manifestation of a MPN and is a significant contributor to both morbidity and mortality. JAK2 plays a role in influencing the proliferation of hematopoietic cells and the inflammatory signaling cascade; mutation in JAK2 is notably associated with higher rates of cellular proliferation and differentiation, as well as cytokine release. Patients with MPNs and JAK2 mutations typically have a raised risk of thrombosis when compared with their counterparts who do not have JAK2 mutations.

High-altitude living is associated with alterations in coagulation pathways and blood composition. Studies demonstrate that otherwise healthy individuals with high-altitude hypoxia are at an increased risk of developing idiopathic arterial and venous thrombosis. Scientists suspect that the high altitude can interact with background hereditary/acquired thrombophilia to further exacerbate the risk of initial/recurrent thrombosis.

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New Model Can Assess Blast Phase Progression Risk in Myeloproliferative Neoplasms

November 12, 2024

Author(s): Alexandra Gerlach, Associate Editor

Researchers from Germany developed a model that utilizes 12 genetic markers to accurately distinguish patients with varying myeloproliferative neoplasms (MPNs) including chronic myeloid leukemia (CML) and BCR::ABL1 negative MPNs polycythemia vera (PV), primary myelofibrosis (PMF), and essential thrombocythemia (ET). Using the model, clinicians can more precisely characterize their disease and determine their risk of progression to blast phase (BP).

Red blood cells and DNA strand | Image Credit: © GustavsMD – stock.adobe.com

MPNs are clonal disorders of the blood cells and bone marrow characterized by abnormal hematopoietic proliferation, which have been differentiated into 8 subclasses by the World Health Organization. However, the 4 classical types are CML, PV, PMF, and ET, characterized by mutations in the JAK2CALR, or MPL driver genes.1,2

Diagnosis of a specific MPN is based on their unique morphology; for example, PV is distinguished by a hypercellular bone marrow and elevated hemoglobin level, compared with ET, which is characterized by megakaryocytic proliferation and increased platelet counts. However, this approach fails to acknowledge overlaps, borderline findings, or potential transitions to other MPN subtypes. Patients with PV and patients with ET can progress to post-PV or post-ET myelofibrosis (MF), underscoring the genetic intricacy of these disorders. There is also the risk of progression to BP, also called leukemic transformation, in which the presence of circulating or bone marrow blasts is ≥20%.2-4

In the study, the researchers aimed to use genetic markers to more effectively stratify CML, PV, PMF, and ET, as well as characterize patients with progression to BP. They developed a machine-learning model based on 12 genetic markers observed in routine analysis to accurately classify MPN subtypes and provide useful prognostic information in a user-friendly decision tree format for clinicians. Using data from over 500 patients, they were able to genetically characterize 355 individuals with 1 of the 4 classic MPNs.1

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Precipio Expands Bloodhound™ MPN Panel by Adding CALR Mutation Subtyping

The unique assay enables laboratories to provide clinicians with more informed treatment decisions for their patients

NEW HAVEN, Conn., Oct. 08, 2024 (GLOBE NEWSWIRE) — Specialty cancer diagnostics company Precipio, Inc. (NASDAQ: PRPO) announces the launch of a new version of its Bloodhound MPN (Myeloproliferative Neoplasm) panel that is now able to distinguish between CALR type 1 and type 2 mutations. The CALR mutation data plays a critical role in disease prognosis and therapeutic decision-making. This differentiation aligns with the latest National Comprehensive Cancer Network (NCCN) guidelines released in August of this year (Version 2.2024—August 8, 2024).

This is the only quantitative PCR-based panel of its kind on the market that distinguishes between CALR Type 1 and Type 2 alongside the other genes relevant to the molecular evaluation of MPN.

“As science and discovery constantly evolve the diagnostic world, Precipio is committed to maintaining its competitive advantage and being at the forefront of our industry,” said Ilan Danieli, Precipio CEO. “Our customers and their patients will continue to benefit from access to cutting-edge technologies combined with the highest clinical value, enhancing patient care.”

Clinical Significance of CALR Subtyping in MPN Management
The inclusion of CALR mutation subtyping is a direct response to the evolving landscape of MPN patient care where understanding the specific type of CALR mutation can influence treatment strategies and outcomes.

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New Insights Emerge on Treatment Outcomes for Accelerated or Blast-Phase Myeloproliferative Neoplasms

In recent years, several new therapies approved by the US Food and Drug Administration for the treatment of acute myeloid leukemia (AML) have been used in the management of accelerated or blast-phase myeloproliferative neoplasms (MPN-AP/BP). However, due to a dearth of prospective data on the efficacy of these therapies in patients with MPN-AP/BP, there remains a lack of consensus regarding their use in this population.1

In a retrospective, multicenter cohort study published in Blood Advances, researchers aimed to address this gap by investigating outcomes among 202 patients with MPN-AP/BP who were diagnosed and treated in the current era of myeloid therapies.1

Study Findings

The results demonstrated a median overall survival (OS) of 0.86 years, with no significant differences observed by first-line treatment type. The most common frontline strategies were intensive chemotherapy, DNA methyltransferase inhibitor (DNMTi)-based regimens, and DNMTi plus venetoclax–based regimens.1

An analysis of 65 patients who went on to receive allogeneic hematopoietic stem cell transplant (allo-HSCT) revealed a median OS of 2.30 years from the time of transplant.

In an interview with Hematology Advisor, study co-author Evan Chen, MD, a medical oncologist at Dana-Farber Cancer Institute and instructor in medicine at Harvard Medical School in Boston, Massachusetts, described 2 main takeaways from the findings: “First, outcomes of patients with MPN-AP/BP remain poor despite intensive chemotherapy and more recently developed, less-intensive venetoclax-based combinations. Second, a bone marrow transplant remains necessary for the possibility of long-term survival in the current treatment era for these patients.”

Despite the poor outcomes observed in this patient population, the present study found that “only 14% of patients were enrolled in clinical trials, and the criteria for assessing response in these patients is heterogeneous,” noted American Society of Hematology (ASH) media expert Ruben A. Mesa, MD, president and executive director of Atrium Health Wake Forest Baptist Comprehensive Cancer Center in Winston-Salem, North Carolina.

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HTR1B Expression and Thrombosis in Patients With Myeloproliferative Neoplasms

In this retrospective study, the researchers evaluated expression levels of HTR1B based on messenger RNA from peripheral blood mononuclear cells obtained from patients with newly diagnosed MPN, in addition to conducting other analyses. The researchers had a goal of evaluating possible differences in expression of this gene across MPN subtypes.

There were 85 patients with newly diagnosed MPN included in the analysis, with a median age of 57 years (range, 23-80). Among these patients, 28 had polycythemia vera (PV), 25 had essential thrombocythemia (ET), and 32 had primary myelofibrosis (PMF). Additionally, comparisons of HTR1B expression included 6 healthy volunteers.

Across MPN subtypes and control individuals, the expression of HTR1B did not significantly differ (P =.3089). However, there was large variation observed in expression levels. The researchers further examined expression levels in the context of other patient factors, including based on whether patients had a thrombotic or non-thrombotic history.

A total of 32 patients were considered to have thrombotic MPNs and 53 patients were considered to have nonthrombotic MPN, with median ages of 57 years in each group. Levels of HTR1B expression were significantly different when analyzed across groups organized by thrombotic MPN, nonthrombotic MPN, or status as control individuals.

The level of HTR1B expression appeared highest among patients with thrombotic MPNs, while levels appeared to not be significantly different between patients with nonthrombotic MPNs and control individuals. Among patients with thrombotic MPNs, there was no statistically significant difference observed in the level of fold-change in HTR1B expression by MPN subtype.

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Researchers Identify INCA033989 as a Potential Treatment for Myeloproliferative Neoplasms

By Alexandra Gerlach, Associate Editor

Data from a study published in Blood demonstrates the therapeutic potential of INCA033989 as the first targeted therapy for myeloproliferative neoplasms (MPNs) that does not interfere with normal blood cell production. Existing therapeutic options for MPNs are effective at symptom management but have high discontinuation rates due to resistance and inadequate drug tolerability. The development of INCA033989 opens pathways to more effective, targeted options with disease-modifying potential without any negative impact on surrounding blood cells.1

The development of INCA033989 has positive implications for the evolving treatment landscape of patients with MPNs. Image Credit: © Anna – stock.adobe.com

MPNs are a group of malignancies characterized by the overproduction of red and white blood cells and is an umbrella for 6 different disease types: myelofibrosis (MF), essential thrombocythemia, chronic myelogenous leukemia, polycythemia vera, chronic neutrophilic leukemia, and chronic eosinophilic leukemia. Calreticulin (CALR) mutations are responsible for disease development in 20% to 30% of patients with MPNs, which can be either insertions or deletions in exon 9 of CALR. The mutated CALRprotein (mutCALR) is responsible for the stable interaction with thrombopoietin receptors (TPO-R), which are crucial for controlling blood cell production.2,3

Janus kinase (JAK) inhibitors, such as ruxolitinib (Jakafi; Incyte Corp), are the recommended treatment options for patients with MF or other MPNs; however, they are associated with adverse effects (AEs), namely grade 3 or 4 anemia. INCA033989 is a high affinity, fully human immunoglobulin G1 selective monoclonal antibody targeting mutCALR-driven oncogenesis to suppress TPO-R signaling, thereby preventing the proliferation and progression of disease. According to data from the original study announcing the development of this agent, there was an observed synergism between INCA033989 and ruxolitinib which resulted in the inhibition of cell proliferation and indicated the ability of INCA033989 to enhance the efficacy of ruxolitinib.3,4

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