Polycythemia Vera (PV): Update on Emerging Treatment Options

Diagnosis and Management of Cardiovascular Risk in Patients with Polycythemia Vera

Polycythemia vera (PV) is a myeloproliferative neoplasm characterized by aberrant myeloid lineage hematopoiesis with excessive red blood cell and pro-inflammatory cytokine production. Patients with PV present with a range of thrombotic and hemorrhagic symptoms that affect quality of life and reduce overall survival expectancy. Thrombotic events, transformation into acute myeloid leukemia, and myelofibrosis are largely responsible for the observed mortality. Treatment of PV is thus primarily focused on symptom control and survival extension through the prevention of thrombosis and leukemic transformation. Patients with PV frequently experience thrombotic events and have elevated cardiovascular risk, including hypertension, dyslipidemias, obesity, and smoking, all of which negatively affect survival. To reduce the risk of thrombotic complications, PV therapy should aim to normalize hemoglobin, hematocrit, and leukocytosis and, in addition, identify and modify cardiovascular risk factors. Herein, we review what is currently known about the associated cardiovascular risk and propose strategies for diagnosing and managing patients with PV.

Advances in management of primary myelofibrosis and polycythaemia vera: Implications in clinical practice

Primary myelofibrosis (PMF) and polycythaemia vera (PV) are rare BCR-ABL1-negative myeloproliferative neoplasms, associated with an increased risk of thrombosis, haemorrhagic complications and progression to fibrosis or leukaemia or fibrosis for PV. Both diseases are characterised by biological and clinical heterogeneity, leading to great variability in their management in routine clinical practice. In this review, we present an updated overview of the diagnosis, prognosis and treatment of PMF and PV, and we discuss how our multidisciplinary expert group based across France translates this evidence-based knowledge into routine clinical practice.

Naltrexone: a Novel Approach to Pruritus in Polycythemia Vera

Background

Pruritus is a characteristic and often debilitating clinical manifestation reported by about 50% of patients with polycythemia vera (PV). Interventions for PV-associated pruritus include phlebotomy, antidepressants, antihistamines, phototherapy, interferon α, myelosuppression, and signaling pathway-specific agents.

Case Presentation

A 40-year-old man presented with Janus kinase 2 (Jak2)-positive PV complicated by intractable pruritus that was not alleviated by multimodal therapy and lifestyle modifications. Following the initiation of naltrexone, the patient experienced immediate relief that has persisted for 2 years.

Conclusions

This case demonstrates a novel approach to the management of PV-associated pruritus. Notably, naltrexone is an affordable, accessible, and potentially effective option for patients with intractable PV pruritus. Future directions involve consideration of case series or randomized clinical trials investigating the efficacy and pathophysiology of naltrexone in treating PV-associated pruritus.

Management of polycythemia vera: A survey of treatment patterns in Italy

OBJECTIVES

Polycythemia vera (PV) is an acquired clonal hematopoietic stem cell disorder characterized by the overproduction of red blood cells. It has long been underlined that there are differences in treatment patterns in routine practice. Therapeutic strategies have also expanded, and in recent years the JAK1/JAK2 inhibitor ruxolitinib has emerged as a second-line therapeutic option in patients who are intolerant to or resistant to hydroxyurea. Determining the impact of changes on practice patterns is of interest, especially for aspects that lack detailed guidance for management.

METHODS

To gain insights into treatment patterns by clinicians treating patients with PV in Italy, we carried out a survey of 60 hematologists and transfusion specialists. The questions covered: treatment of low-risk patients, definition of significant leukocytosis, splenomegaly and excessive phlebotomies, resistance/intolerance to hydroxyurea, use of ruxolitinib, cytoreductive therapy, and vaccines.

RESULTS

In general, the results of the survey indicate that there is a large heterogeneity in management of patients with PV across these areas.

CONCLUSIONS

While helping to provide greater understanding of treatment patterns for patients with PV in Italy, our survey highlights the need for additional clinical studies to obtain more precise guidance for the routine care of patients with PV.

Givinostat-Liposomes: Anti-Tumor Effect on 2D and 3D Glioblastoma Models and Pharmacokinetics

Glioblastoma is the most common and aggressive brain tumor, associated with poor prognosis and survival, representing a challenging medical issue for neurooncologists. Dysregulation of histone-modifying enzymes (HDACs) is commonly identified in many tumors and has been linked to cancer proliferation, changes in metabolism, and drug resistance. These findings led to the development of HDAC inhibitors, which are limited by their narrow therapeutic index. In this work, we provide the proof of concept for a delivery system that can improve the in vivo half-life and increase the brain delivery of Givinostat, a pan-HDAC inhibitor. Here, 150-nm-sized liposomes composed of cholesterol and sphingomyelin with or without surface decoration with mApoE peptide, inhibited human glioblastoma cell growth in 2D and 3D models by inducing a time- and dose-dependent reduction in cell viability, reduction in the receptors involved in cholesterol metabolism (from -25% to -75% of protein levels), and reduction in HDAC activity (-25% within 30 min). In addition, liposome-Givinostat formulations showed a 2.5-fold increase in the drug half-life in the bloodstream and a 6-fold increase in the amount of drug entering the brain in healthy mice, without any signs of overt toxicity. These features make liposomes loaded with Givinostat valuable as potential candidates for glioblastoma therapy.

Ruxolitinib (a JAK2 inhibitor) as an emerging therapy for refractory pruritis in a patient with low-risk polycythemia vera: A case report

INTRODUCTION

Polycythemia vera (PV) is a Philadelphia-negative myeloproliferative neoplasm (MPN) characterized by the overproduction of red blood cells. The presence of JAK2 mutation is detected in up to 99% of patients with PV. Pruritis is commonly encountered in patients with PV and is considered the most troublesome symptom. Multiple treatment modalities are used for treatment; however, their efficacy is variable. Sometimes, pruritis will not improve even by the use of combined therapies. Recently, Ruxolitinib (a JAK2 inhibitor) has been shown to be very effective, especially in patients with refractory pruritis in the setting of other treatment modalities failure.

PATIENT CONCERN

We describe a 55-year-old male with history of low risk PV presented with severe itching despite using different therapies, including phlebotomy and hydroxyurea. His laboratory results on presentation were significant for red blood cells (RBC) of 8.2 × 106/uL (normal = 4.5-5.5), hematocrit (Hct) of 52.8% (normal = 40-50%), platelet count of 519 × 103/uL (normal = 150-400), white blood cells count of 12.3 × 103/uL (normal = 4-10), and basophils count of 0.22 × 103/uL (normal < 0.1).

DIAGNOSIS

PV related refractory pruritis.

INTERVENTION

Pruritis improved dramatically after starting Ruxolitinib therapy with an improvement of hematological parameters (both hematocrit and platelet count).

CONCLUSION

Different treatment modalities have shown to be beneficial in treating PV-related pruritis, but the clinical outcomes are highly variable. This case report aims to shed light on Ruxolitinib as an emerging therapy for the treatment of refractory cases of PV-related pruritis.