scholarly journals Evaluation of Therapeutic Strategies to Reduce the Number of Thrombotic Events in Patients With Polycythemia Vera and Essential Thrombocythemia

2021 ◽  
Vol 10 ◽  
Author(s):  
Douglas Tremblay ◽  
Heidi E. Kosiorek ◽  
Amylou C. Dueck ◽  
Ronald Hoffman

Thrombosis is the largest contributor to morbidity and mortality in patients with polycythemia vera (PV) and essential thrombocythemia (ET). Our understanding of the risk factors and pathophysiology of thrombosis in PV and ET patients is developing, including recent insights into the role of aberrant platelet-neutrophil interactions, JAK2 mutated endothelial cells and the pro-thrombotic inflammatory milieu. To date, few available therapies have demonstrated the ability to reduce the thrombotic burden in patients with these diseases. Although numerous therapeutic agents have been investigated in both PV and ET patients, few studies are designed to assess their impact on thrombotic events. In this review, we first describe the burden of thrombosis in patients with these myeloproliferative neoplasms (MPNs) and briefly explore their pathophysiologic mechanisms. We then critically assess and summarize the evidence behind currently available therapies with attention toward thrombotic endpoints. Finally, we describe a path forward for clinical research in MPNs that involves surrogate endpoint validation, biomarker development, and clinical trial design strategies in order to accurately assess reduction of thrombotic events when evaluating novel therapies.

Hematology ◽  
2017 ◽  
Vol 2017 (1) ◽  
pp. 480-488 ◽  
Author(s):  
Alessandro M. Vannucchi ◽  
Paola Guglielmelli

Abstract Polycythemia vera (PV) and essential thrombocythemia (ET) are chronic myeloproliferative neoplasms that are characterized by thrombohemorrhagic complications, symptom burden, and impaired survival mainly due to thrombosis, progression to myelofibrosis, and transformation to acute leukemia. In this manuscript, we will review the most recent changes in diagnostic criteria, the improvements in risk stratification, and the “state of the art” in the daily management of these disorders. The role of conventional therapies and novel agents, interferon α and the JAK2 inhibitor ruxolitinib, is critically discussed based on the results of a few basic randomized clinical studies. Several unmet needs remain, above all, the lack of a curative approach that might overcome the still burdensome morbidity and mortality of these hematologic neoplasms, as well as the toxicities associated with therapeutic agents.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4082-4082 ◽  
Author(s):  
Mario Tiribelli ◽  
Federico De Marchi ◽  
Daniela Barraco ◽  
Luciana Marin ◽  
Erika Codarin ◽  
...  

Abstract Introduction Evolution to myelofibrosis (MF) represents a relatively rare but always severe event in patients with essential thrombocythemia (ET) and polycythemia vera (PV). Few reports have focused on the clinical and biological features at diagnosis of ET and PV that correlate with progression to MF. Aims and Methods We retrospectively studied a series of patients with post-ET and post-PV MF and compared with a group of ET and PV patients with a long follow-up without myelofibrotic evolution, with the aim to identify prognostic factors for MF. Forty-three patients with post-ET (n=29) and post-PV (n=14) MF followed at our institution were compared with 125 ET and 75 PV patients with at least 9 years of follow-up without evolution. Diagnosis of ET and PV was confirmed according to WHO criteria (including JAK2 analysis, performed since 2006 and study), evolution to MF was defined according to IWG-MRT proposed criteria. The following parameters, available for all patients at diagnosis of ET or ET, were taken into consideration to find prognostic risk factors for myelofibrosis: age, platelet (PLT) count, hemoglobin (Hb) and hematocrit (Hct) levels, white blood cell (WBC) count. Statistical analyses were conducted using Student t test. Results Median time from diagnosis of ET/PV and progression to MF was 156 months (range: 29-314). Comparing baseline characteristics of patients who evolved to MF and those who did not, we did not found any significant correlation. Mean data at diagnosis for patients with (n = 43) or without (n=200) subsequent evolution to MF were as follow: age 52.1 vs 53.1 years (p=0.79), Hb 15.4 vs 15.7 g/dl (p=0.59), Hct 47.2 vs 47.1% (p=0.67), WBC 9.8 vs 9.1 x 109/l (p=0.11), PLT 713 vs 689 x 109/l (p=0.87). Also when considering only the 29 post-ET MF and the 125 ET patients, there was no clinical feature present at diagnosis that could foresee a future myelofibrotic evolution. Conversely, in the 14 post-PV MF and 75 PV patients, progression to MF was predicted only by higher WBC count (11.4 vs 9.3 x 109/l, p=0.046), while no correlation was found with age, Hb, Hct or PLT [Table 1]. Conclusions Concordant with some previous reports, our data suggest a possible role of leucocytosis as an adverse risk factor for progression to MF in patients with PV, though not in ET. Other clinical characteristics present at diagnosis, such as advanced age, anemia or polycythemia and thrombocytosis do not seem to be associated with higher risk of fibrotic evolution in patients with myeloproliferative neoplasms. Disclosures: No relevant conflicts of interest to declare.


Author(s):  
Marco Benati ◽  
Martina Montagnana ◽  
Elisa Danese ◽  
Giovanna De Matteis ◽  
Dino Veneri ◽  
...  

AbstractMyeloproliferative neoplasms (MPNs) are clonal myeloid disorders characterized by the overproduction of mature blood cells. The pathogenetic hallmark of MPNs is the dysregulation of JAK-STAT signaling, usually associated with theIn total 78 patients with a clinical diagnosis of polycythemia vera (PV), essential thrombocythemia (ET) and idiopathic myelofibrosis (IM), made according to the WHO 2008 criteria, were included in the study. Twenty healthy subjects were checked as controls. Quantification ofThe miR-143 expression in MPNs patients was 2.97-fold higher than in controls.Our findings of aberrant miR-143 expression support the concept that factors other than


2019 ◽  
Vol 3 (11) ◽  
pp. 1729-1737 ◽  
Author(s):  
Alessandra Carobbio ◽  
Alberto Ferrari ◽  
Arianna Masciulli ◽  
Arianna Ghirardi ◽  
Giovanni Barosi ◽  
...  

Abstract In the last years, a growing amount of evidence has been produced regarding the role of leukocytosis as a risk factor for thrombosis in patients with myeloproliferative neoplasms, predominantly in polycythemia vera (PV) and essential thrombocythemia (ET). Results from epidemiologic studies on this issue, however, are inconclusive. We conducted a systematic review and meta-analysis of articles published in the last 12 years addressing the issue, according to a predefined protocol. Forty-one articles analyzing >30 000 patients met our inclusion criteria and were deemed of acceptable methodologic quality. In addition to data on thrombosis, data were collected on bleeding, hematologic evolution, secondary cancer, and death. The relative risk (RR) of thrombosis in the presence of leukocytosis was 1.59 (95% CI, 1.40-1.80), mainly accounted for by ET (RR, 1.65; 95% CI, 1.43-1.91) and arterial thrombosis (RR, 1.45; 95% CI, 1.13-1.86) subgroups; the effect was not significant in venous thrombosis alone. Sensitivity analyses considering recurrent events as well as white blood cell estimates adjusted or unadjusted for confounding factors confirmed the primary results. In addition, the pooled RR of studies that tested white blood cell counts in time-dependent models suggested a causative effect of leukocytes in the mechanism that triggers thrombosis. The effect of leukocytosis on bleeding (RR, 1.87; 95% CI, 1.26-2.77) and death (RR, 1.89; 95% CI, 1.59-2.23) was confirmed, whereas conclusions on hematologic evolutions and solid tumors were uncertain. To confirm the accuracy of these results, an investigation on individual patient data in a large collective archive of homogeneous patients is warranted.


Hematology ◽  
2012 ◽  
Vol 2012 (1) ◽  
pp. 571-581 ◽  
Author(s):  
Anna Falanga ◽  
Marina Marchetti

Abstract Thrombosis is a leading cause of morbidity and mortality in patients with Philadelphia chromosome–negative myeloproliferative neoplasms (MPNs), particularly polycythemia vera and essential thrombocythemia. Mechanisms involved in the pathogenesis of the acquired thrombophilic state associated with these diseases include abnormalities of MPN clone–derived blood cells, which display prothrombotic features, and abnormalities of normal vascular cells, which become procoagulant in response to inflammatory stimuli. Ultimately, the release into the blood of elevated levels of procoagulant microparticles by platelets and vascular cells and the increase in the global thrombin generation due to an acquired activated protein C resistance result in a highly prothrombotic scenario in patients with polycythemia vera and essential thrombocythemia. The acquired point mutation in the pseudokinase domain of JAK2 (JAK2V617F) in these disorders is variably associated with thrombosis and, more consistently, with elevations in WBC counts and alterations in biomarkers of blood-clotting abnormalities. The predictive value of these biomarkers for thrombosis remains to be established to identify subsets of patients at elevated risk who may benefit from prophylaxis with antithrombotic drugs.


2003 ◽  
Vol 44 (9) ◽  
pp. 1483-1488 ◽  
Author(s):  
Francesco Passamonti ◽  
Mario Lazzarino

2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Vincenzo Accurso ◽  
Marco Santoro ◽  
Simona Raso ◽  
Angelo Davide Contrino ◽  
Paolo Casimiro ◽  
...  

Splenomegaly is one of the major clinical manifestations of primary myelofibrosis and is common also in other chronic Philadelphia-negative myeloproliferative neoplasms, causing symptoms and signs and affecting quality of life of patients diagnosed with these diseases. We aimed to study the impact that such alteration has on thrombotic risk and on the survival of patients with essential thrombocythemia and patients with Polycythemia Vera (PV). We studied the relationship between splenomegaly (and its grade), thrombosis and survival in 238 patients with et and 165 patients with PV followed at our center between January 1997 and May 2019.


Thrombosis ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-16 ◽  
Author(s):  
Jonathan S. Bleeker ◽  
William J. Hogan

Thrombocytosis is a commonly encountered clinical scenario, with a large proportion of cases discovered incidentally. The differential diagnosis for thrombocytosis is broad and the diagnostic process can be challenging. Thrombocytosis can be spurious, attributed to a reactive process or due to clonal disorder. This distinction is important as it carries implications for evaluation, prognosis, and treatment. Clonal thrombocytosis associated with the myeloproliferative neoplasms, especially essential thrombocythemia and polycythemia vera, carries a unique prognostic profile, with a markedly increased risk of thrombosis. This risk is the driving factor behind treatment strategies in these disorders. Clinical trials utilizing targeted therapies in thrombocytosis are ongoing with new therapeutic targets waiting to be explored. This paper will outline the mechanisms underlying thrombocytosis, the diagnostic evaluation of thrombocytosis, complications of thrombocytosis with a special focus on thrombotic risk as well as treatment options for clonal processes leading to thrombocytosis, including essential thrombocythemia and polycythemia vera.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4687-4687
Author(s):  
Yue Xu ◽  
Changxin Yin ◽  
Han He ◽  
Lingling Shu ◽  
Fuqun Wu ◽  
...  

Abstract Abstract 4687 JAK2 mutation is commonly found in Philadelphia-negative myeloproliferative neoplasms (MPNs). In Western countries, this mutation is found in approximately 96 percent of people with polycythemia vera, half of individuals with essential thrombocythemia or primary myelofibrosis. We used the method of amplification refractory mutation PCR (ARMS-PCR) to investigate MPN patients in China. We focused our study on patients with essential thrombocythemia (ET). ARMS-PCR was used to detect JAK2 V617F mutation in the bone barrow (BM) or peripheral blood of 37 MPN patients, which consisting of 7 ET, 5 polycythemia vera (PV), 5 chronic myeloid leukemia (CML), 5 chronic idiopathic myelofibrosis (CIMF), as well as 15 suspected MPNs. 17 cases of JAK2 V617F mutation (45.9%) were found in 37 patients, including 4 ET (57.1%), 4 PV (80.0%), 3 CIMF (60.0%), 6 suspected MPNs (40.0%). We did not find JAK2 V617F in the patients with CML. Our results indicated that the frequency of JAK2 V617F mutation in bcr/abl-negative MPNs in Chinese is similar to that in MPN patients in Western countries. At the same time, ARMS-PCR can distinguish the mutation is heterozygous or homozygous. Most patients were heterozygous for JAK2 but only a few were homozygous. In conclusion, our study showed that JAK2 V617F mutation frequency in Chinese MPN patients is similar to that in patients with this disorder in the West. It is the major molecular genetic abnormality in bcr-abl negative MPN and it can be used for diagnosis of MPN in China. Disclosures: No relevant conflicts of interest to declare.


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