Real-world treatments and thrombotic events in polycythemia vera patients in the USA

Recurrent ischemic stroke/transient ischemic attack after patent foramen ovale closure: A cohort study

BACKGROUND

Patent foramen ovale (PFO) has been associated with ischemic stroke and transient ischemic attack (TIA). Guidelines recommend PFO closure for stroke prevention in selected patients, but the risk of recurrent stroke remains high compared to the background population. We aimed to evaluate the causes of recurrent stroke/TIA and post-interventional complications in patients after PFO closure.

METHODS

Patients from the Central Denmark Region who underwent PFO closure at Aarhus University Hospital between November 5, 2018, and May 12, 2023, following an ischemic stroke, TIA, amaurosis fugax, or retinal emboli were included. Data on patient demographics, risk factors, procedural details, post-interventional complications, and recurrent stroke/TIA were collected from electronic medical records.

RESULTS

PFO closure was performed in 310 patients (median age: 49 years). During a median follow-up of 2.6 years (interquartile range: 1.5-3.6, 814 total patient-years), recurrent stroke/TIA was observed in 8 patients (2.6%), or 0.98 recurrent strokes per 100 patient-years. Recurrent stroke/TIA was more frequent in patients with hypertension (50.0% vs. 16.9%, p = 0.039). Recurrent stroke/TIA was related to thrombophilia or hematologic conditions entailing hypercoagulability in 62.5% of patients. New-onset atrial fibrillation was observed in 9.4% of patients within 45 days after the procedure. None of these patients subsequently developed an ischemic event. Other adverse outcomes were uncommon.

CONCLUSION

Rates of recurrent ischemic stroke/TIA after PFO closure were comparable to findings in previous trials. Pre-existing vascular risk factors (hypertension), and a hypercoagulable state were associated with recurrent ischemic stroke/TIA.

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.

Characteristics, blood counts, treatments, and clinical outcomes of 5871 patients with polycythemia vera treated in US community practices

OBJECTIVE

This study aimed to describe clinical characteristics-including blood counts and pharmacologic cytoreductive treatment patterns-and outcomes after 6 months of hydroxyurea (HU) treatment among patients with polycythemia vera (PV) in US community practices.

METHODS

This retrospective observational study included adult patients with a PV diagnosis (1JAN2008-31JAN2020) and ≥2 postdiagnosis visits in the iKnowMed electronic health record database (US Oncology Network and non-Network clinics). Suboptimal HU response required ≥1 criterion after ≥3 months of treatment: white blood cell count (WBC) >10 × 109/L, platelet count >400 × 109/L, and/or hematocrit >45%. Patient characteristics were summarized from structured data using descriptive statistics; overall survival was assessed by Kaplan-Meier method.

RESULTS

Among 5871 patients, mean age at diagnosis was 66.1 years (69.8% ≥60 years); 67.2, 59.4, 38.2, and 33.9% of patients had elevated hematocrit, hemoglobin, WBC, and platelets, respectively; 6.1% had a previous thrombotic event. Of 4185 (71.3%) high-risk and 1675 low-risk patients, 55.0 and 32.0% received pharmacologic cytoreductive treatment, most commonly HU (89.8 and 88.9%). After 6 months of pharmacologic cytoreductive treatment, 56.9% had a suboptimal response. Five-year survival probability was 81.5 and 84.3% among patients with suboptimal and optimal responses to HU, respectively, which was not statistically different but suggests potential for survival benefits with longer follow-up.

CONCLUSION

Nearly half of high-risk patients with PV did not receive pharmacologic cytoreductive treatment. Of those who did, over half had suboptimal response, suggesting these patients may need dose adjustments, improved adverse effect management, or alternative treatments. Longer follow-up may be needed to assess an association between HU response and survival.

Pharmacokinetics and Pharmacodynamics of Rusfertide, a Hepcidin Mimetic, Following Subcutaneous Administration of a Lyophilized Powder Formulation in Healthy Volunteers

BACKGROUND AND OBJECTIVE

Hepcidin, an endogenous peptide hormone, binds to ferroportin and is the master regulator of iron trafficking. Rusfertide, a synthetic peptide, is a potent hepcidin mimetic. Clinical studies suggest rusfertide may be effective in the treatment of polycythemia vera. This study investigated the dose-ranging pharmacokinetics, pharmacodynamics, and safety of a lyophilized formulation of rusfertide.

METHODS

A randomized open-label crossover study was conducted in two groups of healthy adult subjects to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of subcutaneous rusfertide doses that ranged from 10 to 60 mg of a lyophilized formulation and 20 mg of an aqueous prefilled syringe formulation that were used in clinical trials.

RESULTS

Rusfertide showed a rapid initial absorption. Median time to peak plasma concentrations for the lyophilized formulation was 24 h for doses of 10-30 mg and 2-4 h for doses of 45 and 60 mg. Mean terminal half-life ranged from 19.6 to 57.1 h. Rusfertide peak concentration and area under the concentration-time curve increased with an increasing dose, but in a less than dose-proportional manner. Metabolites M4 and M9 were identified as major metabolites. At the rusfertide 20-mg dose, the lyophilized formulation had an area under the concentration-time curve from time zero to infinity approximately 1.5-fold higher than the aqueous formulation. The elimination half-life was comparable for the two formulations. Dose-related decreases in serum iron and transferrin-iron saturation were seen following rusfertide treatment. The majority of treatment-emergent adverse events were mild; treatment-related treatment-emergent adverse events seen in ≥10% of subjects were injection-site erythema and injection-site pruritus.

CONCLUSIONS

Rusfertide was well tolerated; the pharmacokinetic and pharmacodynamic results indicate that lyophilized rusfertide is suitable for once-weekly or twice-weekly administration.

Polycythemia vera: past, present and future

There has been remarkable progress in the development of novel therapeutic approaches for patients with polycythemia vera (PV). Historically, therapy goals in PV were to mitigate thrombotic risks and control blood counts and symptoms. There is now increased focus on disease modification through progressive attrition of JAK2-mutant stem/progenitor cells. The approval of ropeginterferon, a novel monoPEGylated interferon, coupled with findings from LOW-PV and longer-term data from CONTINUATION-PV that strongly support a disease-modifying effect for interferon therapy, have transformed the treatment paradigm for this disorder. Results from MAJIC-PV demonstrate that disease modification can also be induced with JAK inhibitors, suggesting an urgent need to incorporate prospective molecular monitoring into PV trials. Novel agents, such as hepcidin mimetics, aim to help patients with PV restore normal hematocrit levels and become phlebotomy-free. In this review, we will summarize past, current and future approaches to PV management and highlight findings from key clinical studies.

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.

Impact of gender representativeness in online symptom survey and clinical trial participation among patients with myeloproliferative neoplasms

Patients with myeloproliferative neoplasms (MPNs) face chronic symptom burden. Online symptom assessment studies allow for recruitment of large numbers of motivated patients, but patient self-selection can lead to sampling bias. This study evaluated how gender representativeness in MPN symptom surveys and trials impacted symptom score mean estimates, using data from 4825 survey respondents and 291 trial participants with MPNs. The survey data showed that men participated at a rate roughly 50% less than what would be expected based on prevalence, and women reported higher scores than men on average for six of 10 symptoms. Together, this led to potential over estimation in six of 10 symptom score means (ranging from 5.8% to 15.3% overestimated). The trial data showed less gender-based sampling bias compared to the survey data. Studies utilizing online symptom surveys should implement study design features to recruit more men, assess for gender participation imbalances, and provide weighted estimates where appropriate.

Contemporary Challenges in Polycythemia Vera Management From the Perspective of Patients and Physicians

Although polycythemia vera (PV) is a chronic and incurable disease, effective management can allow most patients to maintain functional lives with near-normal life expectancy. However, there remain several inter-related factors that contribute to many ongoing challenges associated with the management of PV, which this review aims to explore. First, as a disease hallmarked by constitutive activation of the JAK/STAT pathway, PV is often accompanied by inflammatory symptoms that negatively impact quality of life. Next, patients often require recurrent therapeutic phlebotomies to maintain their hematocrit below the 45% threshold that has been associated with a decreased risk of thrombotic events. The need to closely monitor hematocrit and perform conditional therapeutic phlebotomies ties patients to the healthcare system, thereby limiting their autonomy. Furthermore, many patients describe therapeutic phlebotomies as burdensome and the procedure is often poorly tolerated, further contributing to quality-of-life decline. Phlebotomy needs can be reduced by utilizing cytoreductive therapy; however, standard first-line cytoreductive options (i.e., hydroxyurea and interferon) have not been shown to significantly improve symptom burden. Collectively, current PV management, while reducing thrombotic risk, often has a negative impact on patient quality of life. As researchers continue to advance towards the goal of developing a disease-modifying therapy for patients with PV, pursuit of nearer-term opportunities to shift the current treatment paradigm towards improving symptoms without compromising quality of life is also warranted, for example, by reducing or eliminating the frequent use of phlebotomy.

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.

Rusfertide, a Hepcidin Mimetic, for Control of Erythrocytosis in Polycythemia Vera

BACKGROUND

Polycythemia vera is a chronic myeloproliferative neoplasm characterized by erythrocytosis. Rusfertide, an injectable peptide mimetic of the master iron regulatory hormone hepcidin, restricts the availability of iron for erythropoiesis. The safety and efficacy of rusfertide in patients with phlebotomy-dependent polycythemia vera are unknown.

METHODS

In part 1 of the international, phase 2 REVIVE trial, we enrolled patients in a 28-week dose-finding assessment of rusfertide. Part 2 was a double-blind, randomized withdrawal period in which we assigned patients, in a 1:1 ratio, to receive rusfertide or placebo for 12 weeks. The primary efficacy end point was a response, defined by hematocrit control, absence of phlebotomy, and completion of the trial regimen during part 2. Patient-reported outcomes were assessed by means of the modified Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) patient diary (scores range from 0 to 10, with higher scores indicating greater severity of symptoms).

RESULTS

Seventy patients were enrolled in part 1 of the trial, and 59 were assigned to receive rusfertide (30 patients) or placebo (29 patients) in part 2. The estimated mean (±SD) number of phlebotomies per year was 8.7±2.9 during the 28 weeks before the first dose of rusfertide and 0.6±1.0 during part 1 (estimated difference, 8.1 phlebotomies per year). The mean maximum hematocrit was 44.5±2.2% during part 1 as compared with 50.0±5.8% during the 28 weeks before the first dose of rusfertide. During part 2, a response was observed in 60% of the patients who received rusfertide as compared with 17% of those who received placebo (P = 0.002). Between baseline and the end of part 1, rusfertide treatment was associated with a decrease in individual symptom scores on the MPN-SAF in patients with moderate or severe symptoms at baseline. During parts 1 and 2, grade 3 adverse events occurred in 13% of the patients, and none of the patients had a grade 4 or 5 event. Injection-site reactions of grade 1 or 2 in severity were common.

CONCLUSIONS

In patients with polycythemia vera, rusfertide treatment was associated with a mean hematocrit of less than 45% during the 28-week dose-finding period, and the percentage of patients with a response during the 12-week randomized withdrawal period was greater with rusfertide than with placebo. (Funded by Protagonist Therapeutics; REVIVE ClinicalTrials.gov number, NCT04057040.).

Cytoreduction for ET and PV: who, what, when, and how?

Thrombotic complications are the primary contributor to morbidity and mortality in essential thrombocythemia (ET) and polycythemia vera (PV). Cytoreductive therapy is the main tool for primary or tertiary thrombosis prevention in these diseases. In general, high-thrombotic-risk patients and those with symptoms that may be ameliorated from cytoreductive therapy are candidates for this treatment, although the decision is highly individualized. Approved options for cytoreduction in ET and PV include hydroxyurea, long-acting interferons, anagrelide in ET, and ruxolitinib in PV. Selecting the ideal agent requires careful consideration of the toxicity profiles and individual treatment goals. In this review the existing literature on cytoreductive decisions in ET and PV is summarized, with an emphasis on risk-stratification, highlighting the need for personalized care in order to maximize the benefit of these therapies while minimizing toxicities.

Association of inflammation and abnormal lipid metabolism with risk of thrombosis and thrombosis progression in patients with polycythemia vera: a retrospective study

To date, no therapeutic strategy has been shown to be effective in reducing the risk of polycythemia vera (PV) transforming into myelofibrosis or leukemia, and the main goal of current treatment is to prevent thrombotic events. Recent studies have shown that higher levels of inflammation are associated with an increased risk of thrombosis in PV patients, while the correlation between inflammation and abnormal lipid metabolism with the risk of thrombosis in PV has not been reported. In this retrospective study, 148 patients with newly diagnosed PV who visited the Affiliated Hospitals of Nanchang University from January 2013 to June 2023 were categorized into low-risk group and high-risk group according to the risk of thrombosis, and were subsequently divided into thrombosis non-progression group and progression group. The differences of novel inflammatory markers PHR, NHR, MHR, LHR, and SIRI in each group were analyzed and compared with healthy adults who underwent physical examination in the hospitals during the same period. The results showed that PHR, NHR, MHR, and SIRI levels were significantly higher in the PV group than in the control group (P < 0.001), while HDL-C levels were considerably lower (1.09 vs. 1.31, P < 0.001). Comparisons within the groups of PV patients revealed that PHR, MHR, NHR, NLR, and SIRI levels were significantly higher in the high-risk group for thrombosis than in the low-risk group (P < 0.01); the thrombosis PHR, NHR, NLR, and SIRI levels were higher in the group with progression of thrombosis than in the group without progression of thrombosis (P < 0.05), while HDL-C levels were significantly lower (1.02 vs. 1.12, P < 0.001). The results of the ROC curve analysis showed that NHR (AUC = 0.791), HDL-C (AUC = 0.691), PHR (AUC = 0.668), NLR(AUC = 0.658), and SIRI (AUC = 0.638) had high diagnostic efficacy for identifying PV patients with thrombosis progression. Multivariate analysis showed that NHR, NLR, MHR, and LHR were independent risk factors for PV patients with thrombosis progression (P < 0.05). Kaplan-Meier survival curves showed that NHR ≥ 5.82 × 109/mmol, NLR ≥ 6.295, PHR ≥ 280.4 × 109/mmol, MHR ≥ 0.295 × 109/mmol, LHR ≥ 1.41 × 109/mmol, and SIRI ≥ 1.53 × 109/L were risk factors for PFS in PV patients. The study demonstrates for the first time that novel inflammatory markers PHR, NHR, MHR, LHR, and SIRI may be used as new predictors for PV patients with thrombosis progression. NHR has the highest value in predicting thrombosis in PV patients and is superior to NLR which was reported previously.

Moving toward disease modification in polycythemia vera

Polycythemia vera (PV) belongs to the BCR-ABL1-negative myeloproliferative neoplasms and is characterized by activating mutations in JAK2 and clinically presents with erythrocytosis, variable degrees of systemic and vasomotor symptoms, and an increased risk of both thromboembolic events and progression to myelofibrosis and acute myeloid leukemia (AML). Treatment selection is based on a patient's age and a history of thrombosis in patients with low-risk PV treated with therapeutic phlebotomy and aspirin alone, whereas cytoreductive therapy with either hydroxyurea or interferon alfa (IFN-α) is added for high-risk disease. However, other disease features such as significant disease-related symptoms and splenomegaly, concurrent thrombocytosis and leukocytosis, or intolerance of phlebotomy can constitute an indication for cytoreductive therapy in patients with otherwise low-risk disease. Additionally, recent studies demonstrating the safety and efficacy (ie, reduction in phlebotomy requirements and molecular responses) of ropegylated IFN-α2b support its use for patients with low-risk PV. Additionally, emerging data suggest that early treatment is associated with higher rates of molecular responses, which might eventually enable time-limited therapy. Nonetheless, longer follow-up is needed to assess whether molecular responses associate with clinically meaningful outcome measures such as thrombosis and progression to myelofibrosis or AML. In this article, we provide an overview of the current and evolving treatment landscape of PV and outline our vision for a patient-centered, phlebotomy-free, treatment approach using time-limited, disease-modifying treatment modalities early in the disease course, which could ultimately affect the natural history of the disease.

Ropeginterferon versus Standard Therapy for Low-Risk Patients with Polycythemia Vera

BACKGROUND: Whether phlebotomy alone can adequately maintain target hematocrit in patients with low-risk polycythemia vera (PV) remains elusive. METHODS: In a phase 2 open-label randomized trial, we compared ropeginterferon alfa-2b (ropeg; 100 μg every 2 weeks) with phlebotomy only regarding maintenance of a median hematocrit level (≤45%) over 12 months in the absence of progressive disease (primary end point). In follow-up, crossover to the alternative treatment group was allowed if the primary end point was not met. RESULTS: In total, 127 patients were enrolled (ropeg: n=64; standard group: n=63). The primary end point was met in 81% and 51% in the ropeg and standard groups, respectively. Responders continued the assigned treatment until month 24 and maintained response in 83% and 59%, respectively (P=0.02). Ropeg responders less frequently experienced moderate/severe symptoms (33% vs. 67% in the standard group) and palpable splenomegaly (14% vs. 37%) and showed normalization of ferritin levels and blood counts. Nonresponders at 12 months crossed over to the standard (n=9) or ropeg (n=23) group; in patients switched to ropeg only, 7 of 23 met the response criteria in 12 months, and phlebotomy need was high (4.7 per patient per year). Discontinuation because of adverse events occurred in seven patients treated with ropeg. CONCLUSIONS: In this 24-month trial, ropeg was superior to phlebotomy alone in maintaining hematocrit on target. No dose-limiting side effects or toxicities were noted; 9.2% of patients on ropeg and no patients on standard treatment developed neutropenia. (Funded by AOP Health and others; ClinicalTrials.gov number, NCT03003325.)