The Myeloproliferative Neoplasm Landscape: A Patient's Eye View

Advances in the design and discovery of next-generation janus kinase-2 (JAK2) inhibitors for the treatment of myeloproliferative neoplasms

INTRODUCTION

Myeloproliferative neoplasms (MPNs) are rare hematopoietic disorders driven by mutations in the JAK-STAT signaling pathway genes. While JAK2 inhibitors have transformed MPN treatment, they do not eliminate the malignant clone or prevent disease progression in most patients. This limitation underscores the need for more effective therapies.

AREA COVERED

This review examines the evolution of JAK2 inhibitors for treating MPNs. Current JAK2 inhibitors primarily function as type I inhibitors, targeting the active kinase conformation, but their effectiveness is limited by ongoing JAK-STAT signaling. To overcome these limitations, next-generation therapies, such as type II JAK2 inhibitors and pseudokinase domain inhibitors, are being developed to target inactive kinase conformations and alternative signaling pathways. Furthermore, combination therapies with PI3K, mTOR, CDK4/6 inhibitors, and epigenetic modulators are being investigated for their potential synergistic effects, aiming for deeper and more durable responses in MPN patients.

EXPERT OPINION

Next-generation JAK2 inhibitors are needed to enhance current MPNs treatments by overcoming resistance, improving selectivity, targeting specific patient groups, and exploring combination therapies. Addressing challenges in drug design, preclinical testing, and clinical trials is crucial. Developing dual or multiple inhibitors targeting JAK2 and other MPN-related pathways is urgent to address complex signaling networks and improve efficacy.

Burden of Symptoms and Symptom Experience of Filipino Patients with Myeloproliferative Neoplasm: A Qualitative Phenomenological Approach

Background

Myeloproliferative neoplasms (MPN) are a heterogeneous group of disorders characterized by the cellular proliferation of one or more hematologic cell lines. Patients with MPN who are Philadelphia-negative such as those with Polycythemia Vera (PV), Essential Thrombocytosis (ET), or Myelofibrosis (MF) experience a cluster of symptoms related to the disease activity which can affect their quality of life.

Objectives

This study aimed to explore the symptoms and symptom experience as well as lived experience of Filipino patients with MPN using a qualitative phenomenological approach to get a deeper understanding of the disease symptomatology.

Methods

Twenty-three patients with myeloproliferative neoplasms were purposively selected according to: 1) type of MPN (PV, ET, MF) 2) status of MPN disease (newly diagnosed vs. chronic) 3) age (≤50 years old; >50 years) and 4) sex (male vs. female). The investigators conducted key informant interviews using a semi-structured interview guide. Interview scripts and narratives were transcribed and analyzed using categorical aggregation and thematic analysis.

Results

Twenty patients proceeded with the interview (8 PV, 6 ET, 6 MF). The meta-themes identified were 1) symptom experience and 2) disease perception. Three sub-themes under symptom experience were a) heterogenous and complex symptomatology; b) dynamic nature of symptoms; c) living and coping with symptoms. Three sub-themes under disease perception were a) struggle with the concept of the disease; b) anxiety and uncertainty; c) acceptance and hope. The most common symptoms experienced by the patients were fatigue, bone pain, and abdominal discomfort. Vascular symptoms specifically headache, numbness, and problems in concentration were commonly reported by patients with PV. Fever and weight loss were the least common. Sources of anxiety/uncertainty include the unpredictability of symptom occurrence and blood counts, the burden of taking maintenance medications, the financial burden of living with MPN, and the unpredictability of disease and complications.

Conclusion

Patients with MPN had heterogenous, co-occurring, and dynamic symptoms which affected their overall productivity both at home and at work. Patients with MF had the most symptom burden while patients with ET had the least. This study provided valuable insights on disease perceptions, sources of anxiety, and coping mechanisms of patients with MPN. A deeper understanding of the symptom experience and disease perceptions of the patients will enhance the physician-patient interaction especially when discussing management options.

Management of classical Philadelphia chromosome-negative myeloproliferative neoplasms in Asia: consensus of the Asian Myeloid Working Group

Myeloproliferative neoplasms (MPN) are a heterogeneous group of clonal hematopoietic stem cell disorders characterized clinically by the proliferation of one or more hematopoietic lineage(s). The classical Philadelphia-chromosome (Ph)-negative MPNs include polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The Asian Myeloid Working Group (AMWG) comprises representatives from fifteen Asian centers experienced in the management of MPN. This consensus from the AMWG aims to review the current evidence in the risk stratification and treatment of Ph-negative MPN, to identify management gaps for future improvement, and to offer pragmatic approaches for treatment commensurate with different levels of resources, drug availabilities and reimbursement policies in its constituent regions. The management of MPN should be patient-specific and based on accurate diagnostic and prognostic tools. In patients with PV, ET and early/prefibrotic PMF, symptoms and risk stratification will guide the need for early cytoreduction. In younger patients requiring cytoreduction and in those experiencing resistance or intolerance to hydroxyurea, recombinant interferon-α preparations (pegylated interferon-α 2A or ropeginterferon-α 2b) should be considered. In myelofibrosis, continuous risk assessment and symptom burden assessment are essential in guiding treatment selection. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) in MF should always be based on accurate risk stratification for disease-risk and post-HSCT outcome. Management of classical Ph-negative MPN entails accurate diagnosis, cytogenetic and molecular evaluation, risk stratification, and treatment strategies that are outcome-oriented (curative, disease modification, improvement of quality-of-life).

Effect of hypoxia on HIF-1α and NOS3 expressions in CD34+ cells of JAK2V617F-positive myeloproliferative neoplasms

PURPOSE

Myeloproliferative neoplasms (MPN) are a heterogeneous group of hematopoietic stem-cell diseases with excessive proliferation of one or more blood cell lines. In this study, we evaluated the effect of different oxygen concentrations on HIF-1α and NOS3 gene expression to determine the effect of the bone marrow microenvironment on JAK2V617F positive Philadelphia chromosome negative (Ph-) MPNs.

PATIENTS AND METHODS

Peripheral blood mononuclear cells (MNC) of 12 patients with Ph- MPN were collected. The presence of JAK2V617F allele status was determined with allele-specific nested PCR analysis. MPN CD34+ and CD34depleted populations were isolated from MNC by magnetic beads. Separate cell cultures of CD34+/depleted populations were managed at different oxygen concentrations including anoxia (∼0%), hypoxia (∼3%), and normoxia (∼20%) conditions for 24 ​h. HIF-1α and NOS3 gene expression changes were examined in each population related to JAK2V617F status with real time RT-PCR.

RESULT

It was revealed that relative HIF-1α and NOS3 expressions were significantly increased in response to decreased oxygen concentration in all samples. Relative HIF-1α and NOS3 expressions were found to be higher especially in CD34+ and CD34depleted populations carrying JAK2V617F mutations compared to MPN patients carrying wild-type JAK2.

CONCLUSION

JAK2V617F might have specific role in HIF-1α and NOS3 regulations with respect to low oxygen concentrations in Ph- MPN. Further evaluations might reveal the effect of JAK2V617F on Ph- MPN pathogenesis in bone marrow microenvironment.

Persistent suffering: Living experiences of patients with rare disease: An interpretative phenomenological study

BACKGROUND

The low prevalence of rare diseases has caused the need for studies in this field to be neglected. Regardless of the prevalence of rare diseases, many people around the world have to live with the medical, psychological, and social consequences of their condition. Individuals with rare diseases may face challenges that are different from those experienced in more common medical conditions. The life experiences of patients with rare diseases have not been sufficiently investigated. The purpose of this study was to discover the meaning of living as a person with a rare disease.

MATERIALS AND METHODS

This interpretative phenomenological study was conducted in 2021-2022 on 10 patients with one of the rare diseases (registered in the Atlas of Rare Diseases of Iran). Based on purposeful sampling, people with rare diseases living in Mazandaran, Golestan, and Tehran provinces were invited to participate in the study. Data collection was done using open and semi-structured interviews. The research question was exploring understanding the experience and meaning of life as a person with a rare disease. Van Manen's interpretive phenomenological approach was used to analyze the data, and the criteria of validity, transferability, and verifiability were used to ensure the trustworthiness of the research.

RESULTS

The five main themes "permanent suffering, such as a bird in a cage, rejection, immersion in the whirlpool of thoughts, losing the feeling of life", and 10 sub-themes "nightmare, giving up, deprivation, limitation, worthlessness, being stigmatized, dark vision, confusion, continuous regret, and inferiority feeling" were extracted.

CONCLUSION

The results of this study show that the suffering of the disease casts a shadow on all aspects of a patient's life with a rare disease. The effects of illness, disability, limitations, and exclusions had created a human being in a cage, whose right to live like others has been denied.

Putative Role of Neutrophil Extracellular Trap Formation in Chronic Myeloproliferative Neoplasms

Myeloproliferative neoplasms (MPNs) are hematologic malignancies characterized by gene mutations that promote myeloproliferation and resistance to apoptosis via constitutively active signaling pathways, with Janus kinase 2-signal transducers and the activators of transcription (JAK-STAT) axis as a core part. Chronic inflammation has been described as a pivot for the development and advancement of MPNs from early stage cancer to pronounced bone marrow fibrosis, but there are still unresolved questions regarding this issue. The MPN neutrophils are characterized by upregulation of JAK target genes, they are in a state of activation and with deregulated apoptotic machinery. Deregulated neutrophil apoptotic cell death supports inflammation and steers them towards secondary necrosis or neutrophil extracellular trap (NET) formation, a trigger of inflammation both ways. NETs in proinflammatory bone marrow microenvironment induce hematopoietic precursor proliferation, which has an impact on hematopoietic disorders. In MPNs, neutrophils are primed for NET formation, and even though it seems obvious for NETs to intervene in the disease progression by supporting inflammation, no reliable data are available. We discuss in this review the potential pathophysiological relevance of NET formation in MPNs, with the intention of contributing to a better understanding of how neutrophils and neutrophil clonality can orchestrate the evolution of a pathological microenvironment in MPNs.

State-of-the-Art Review on Myelofibrosis Therapies

Myelofibrosis (MF) is a BCR-ABL1-negative myeloproliferative neoplasm characterized by anemia, extramedullary hematopoiesis, bone marrow fibrosis, splenomegaly, constitutional symptoms and acute myeloid leukemia progression. Currently, allogeneic haematopoietic stem cell transplantation (AHSCT) therapy is the only curative option for MF patients. However, AHSCT is strictly limited due to the high rates of morbidity and mortality. Janus kinase 2 (JAK2) inhibitor Ruxolitinib is the first-line treatment for intermediate-II or high-risk MF patients with splenomegaly and constitutional symptoms, but most MF patients develop resistance or intolerance to Ruxolitinib. Therefore, MF treatment is a challenge for the medical community. This review summarizes 3 investigated directions for MF therapy: monotherapies of JAK inhibitors, monotherapies of non-JAK targeted agents, combination therapies of Ruxolitinib and other agents. We emphasize combination of Ruxolitinib and other agents is a promising strategy.

Neutrophil Death in Myeloproliferative Neoplasms: Shedding More Light on Neutrophils as a Pathogenic Link to Chronic Inflammation

Neutrophils are an essential component of the innate immune response, but their prolonged activation can lead to chronic inflammation. Consequently, neutrophil homeostasis is tightly regulated through balance between granulopoiesis and clearance of dying cells. The bone marrow is both a site of neutrophil production and the place they return to and die. Myeloproliferative neoplasms (MPN) are clonal hematopoietic disorders characterized by the mutations in three types of molecular markers, with emphasis on Janus kinase 2 gene mutation (JAK2V617F). The MPN bone marrow stem cell niche is a site of chronic inflammation, with commonly increased cells of myeloid lineage, including neutrophils. The MPN neutrophils are characterized by the upregulation of JAK target genes. Additionally, MPN neutrophils display malignant nature, they are in a state of activation, and with deregulated apoptotic machinery. In other words, neutrophils deserve to be placed in the midst of major events in MPN. Our crucial interest in this review is better understanding of how neutrophils die in MPN mirrored by defects in apoptosis and to what possible extent they can contribute to MPN pathophysiology. We tend to expect that reduced neutrophil apoptosis will establish a pathogenic link to chronic inflammation in MPN.

A Cross-sectional Study of Patients and Physicians on the Impact of Myeloproliferative Neoplasms on Patient Health: The Landmark Survey From Taiwan

Patients with myeloproliferative neoplasm (MPN), including myelofibrosis, polycythemia vera, and essential thrombocythemia, experience a pronounced symptom burden. This study aimed to collect information from physicians and patients in Taiwan to explore their perceptions regarding MPN, treatment goals, and satisfaction with disease management. A cross-sectional, online survey was conducted among patients and physicians from September 2018 to November 2018 in Taiwan as a subset of the expansion of the Landmark survey. Overall, 50 patients with MPN and 30 physicians participated in this study. The symptom burden was low, with the mean number of symptoms experienced being 1.8. The most frequent symptom per physicians’ perception was fatigue, whereas it is not the most common symptom from MPN patients’ perspective. Blood count was the key indicator to determine treatment success from patients’ view, whereas presence of a new symptom was the key indicator from physicians’ perspective. Concordant with previous studies, our study revealed a lack of alignment between physician and patient perceptions relating to treatment goals and disease management. Nevertheless, the physical, emotional, work/activities and financial impacts on patients were minimal in Taiwan.

Clinical characteristics, prognostic factors, and outcomes of patients with essential thrombocythemia in Japan: the JSH-MPN-R18 study

We conducted a large-scale, nationwide retrospective study of Japanese patients who were diagnosed with essential thrombocythemia based on the diagnostic criteria in the World Health Organization classification. We investigated clinical characteristics, survival rates, and the incidence of thrombohemorrhagic events as well as risk factors for these events. A total of 1152 patients were analyzed in the present study. Median age at diagnosis was 65 years, the median platelet count was 832 × 10⁹/L, and the positive mutation rates of JAK2V617F, CALR, and MPL were 62.8, 25.1, and 4.1%, respectively. Compared with European and American patients, Japanese patients were more likely to have cardiovascular risk factors and less likely to have systemic symptoms including palpable splenomegaly. Thrombocytosis was identified as a risk factor for hemorrhagic events and prognosis, but not for thrombotic events. The prognostic factors and risk classifications reported in Europe and the United States were generally applicable to Japanese patients. Regarding transformations, secondary myelofibrosis progressed in a time-dependent manner, but progression to acute leukemia was low in "true" ET patients. Skin cancers were less common and gastrointestinal cancers more common as secondary malignancies in Japanese patients, suggesting ethnic differences.

Living with an MPN in Ireland: patients' and caregivers' perspectives

Myeloproliferative neoplasms (MPNs) are associated with a high disease burden, reduced quality of life and shortened survival. The aim of this questionnaire was to gain patients' and caregivers' perspectives on the impact of living with an MPN in the Republic of Ireland. An Irish adaptation of the 'Global MPN Landmark survey' was conducted. Fifty-one patients and 44 caregivers completed the questionnaire. Patients reported a wide variety of symptoms at the time of questionnaire completion; fatigue, bone pain and pruritus being most frequently reported. Approximately one-third of respondents from each of the groups (patients and caregivers) reported a negative impact of MPNs on their emotional wellbeing and daily lives. The study findings revealed that, despite treatment, symptom burden remains high, and several unmet needs exist, including educational, emotional and peer group support. Interventions that focus on reducing symptom burden and addressing these unmet needs, may improve the quality of life for patients with MPNs and their caregivers.

Essential Thrombocythemia in a 15-Year-Old Female: Presentation, Workup, and Treatment Considerations in the Pediatric Population

Essential thrombocythemia (ET) is a diagnosis most often seen in adults but can also present in children in rare cases. This article reviews the presentation, diagnosis, and treatment of ET in a 15-year-old female followed by a review of the literature regarding special considerations in the workup, diagnosis, treatment, and follow-up of ET in the pediatric population.