Classical Myeloproliferative Neoplasms Research Articles

PB2195 ASSESSMENT OF PLATELET MEMBRANE ALTERATION IN PATIENTS WITH MYELOID METAPLASIA WITH MYELOFIBROSIS

Background:Patients with Myeloid Metaplasia with Myelofibrosis (MMM) present at the onset or during evolution thrombotic complications. In the assessment of thrombosis risk are important the presence of JAK2 mutation as well as platelet function. Receptors that define the status of activated platelets (CD62P, CD36) are better expressed in chronic myeloproliferative neoplasms (MPNs) patients with thrombotic complications. Numerous studies have shown a high oxidative status in MPNs patients, a situation that correlates with a higher thrombotic risk.Aims:The aim of our study was to determine if resting membrane potential could be correlated with alterations in expression of platelet receptors and reactive species production (ROS)MethodsThis retrospective study included 35 patients with MMM (16 male and 19 female), median age 61.1 (95% CI of median 60,71‐72) as well as 15 healthy volunteers. The diagnosis of MMM was made according to World Health Organization (WHO) classification of MPNs. We evaluated the flow cytometry markers of platelet adhesion (CD42a, CD42b), aggregation (CD41, CD61) and CD36. Production of reactive species (ROS) was examined using fluorescence method with DCFDA and was assessed by aria under curve (AUC) in serial measurements during 900 sec. The determination of platelet membrane potential was done by fluorescence method using 3,3′‐dipropyl‐2,2′‐thiadicarbocyanine iodide (DiSC3‐5)Results:The ROS production is significantly higher in MMM group: median value of AUC patient group 12780882862,5000 compared with controls 11621365017,5000, p= 0.04. Patients in advanced phase (grade 5 Hackett of splenomegaly) has high level of ROS production compared with patients diagnosed in early stage (grade 1 or 2 Hackett of splenomegaly) median value: 13178014970 vs 12303298585, p = 0.001. There are no differences between groups that was splitted by type of treatment Ruxolitinib/Hydroxiureea or type of mutation diagnosed JAK2V617F/CALR/no mutation. Patients with MMM present higher resting membrane potential (RMP) compared with controls (median value ‐ 63 mV vs–57.5 mV, p = 0.05). The expression of CD36 receptor was higher in MMM group vs controls: median value 27.91 vs 20.91, p = 0.003. Number of microparticle (MP) derivated from platelet, erythrocyte and endothelial cells are no different between patient and control group. We obtain only lower receptor expression on MP surface for CD41/CD61, CD42b and GlyA in patient group compared with control group, p < 0.05. There are significant correlation between resting membrane potential and expression of CD42b (r ‐0.45, p = 0.04) and GlyA receptors (r ‐0.45, p = 0.04).Summary/Conclusion:Patients with MMM especially those with have a higher level of ROS production especially in advanced phase. The hyperpolarisation of cell macrophages membrane could be associated with high ROS production, no reports are regarding platelet membrane. In our study we did not obtain any significant correlation between RMP and ROS production. The expression of CD 36 is higher in MMM patients but was not correlated with ROS production. It was proved that generation of intracellular ROS is associated with CD36 signaling and represent one start point for thrombosis. Low expression of CD42b and GlyA of microparticle surface is associated with lower RMP that correspond to activated status of platelet membrane. We have to verify these results in higher number of patients in order to find significant correlations

S888 TNF‐ALPHA PROMOTES CLONAL EXPANSION OF KIT D816V+ CELLS IN SYSTEMIC MASTOCYTOSIS

Background:Systemic mastocytosis (SM) is characterized by clonal mast cell (MC) infiltration in the bone marrow (BM). Most patients harbor the activating KIT mutation D816V. Cytokines are substantially involved in the interactions between neoplastic cells and the BM microenvironment in SM and in classical myeloproliferative neoplasms (MPN) and have been recognized as a major trigger of disease evolution. The pro‐apoptotic/anti‐proliferative and pro‐inflammatory cytokine tumor necrosis factor alpha (TNFa) has been identified as an important driver for the expansion of JAK2 V617F+ clones and the establishment of MPN.Aims:Investigation of the potential role of TNFa in disease evolution of SM patients.Methods:In vitro and in vivo experiments with MC lines and primary material of SM patients.Results:In a first step, lentivirally‐driven expression of the KIT D816V mutant gene in the human Mo7e cells suggested an oncogene‐dependent regulation of the production of TNFa. Correspondingly, the human neoplastic KIT D816V+ MC lines HMC‐1.2 and ROSAKIT D816V expressed and secreted substantial amounts of TNFa and inhibition of KIT D816V either by the recently approved multi‐kinase inhibitor midostaurin or by RNAi‐mediated knockdown of KIT significantly reduced expression of this cytokine. Mechanistically, we studied auto‐/paracrine effects of TNFa on the clonal selection of neoplastic MC using KIT D816V negative (ROSAKIT WT) and positive (ROSAKIT D816V) subclones of ROSA cells. TNFa reduced proliferation of ROSAKIT WT cells (84.9% ± 4.6% of control, p<0.01) whereas ROSAKIT D816V cells were resistant to TNFa (102.7% ± 3.7% of control, n.s.). Preliminary data also indicate a relative resistance of primary neoplastic cells obtained from KIT D816V+ SM patients against TNFa in colony‐forming unit (CFU) assay. To determine the mechanism of TNFa resistance in KIT D816V+ cells, we screened for key regulators of apoptosis and identified the anti‐apoptotic protein survivin to be highly upregulated in KIT D816V+ ROSA cells upon TNFa treatment but not in KIT D816V‐ ROSA cells. We hypothesize that KIT D816V+ MC produce substantial amounts of TNFa that induces apoptosis and suppresses proliferation of normal BM cells while MC themselves are relatively resistant via upregulation of survivin. In a next step, we studied the effect of TNFa on growth of neoplastic MC in vivo in a xenotransplant model using ROSAKIT D816V cells with and without knockout of TNFa in NOD‐SCID IL‐2Rγ‐null (NSG) mice. CRISPR/Cas9‐mediated knockout completely abolished expression and secretion of TNFa in ROSAKIT D816V cells and resulted in a significantly longer survival of mice compared to mice injected with TNFa expressing controls (median 49 vs. 58 days, p < 0.05). Finally, the clinical relevance of TNFa expression was studied in a SM patient's cohort (n = 45). TNFa levels in sera of patients were significantly higher (median 1.95, range 0.72–16.64 pg/ml, p = 0.002) compared to age‐ and sex‐matched controls (median 1.49, range 0.51–5.63 pg/ml). Importantly, when we stratified SM patients into those with clearly elevated TNFa levels and those with TNFa levels within the reference range of controls (≤3.63 pg/ml) a significantly lower overall survival was observed for SM patients with high TNFa serum levels (median 6.3 years vs. not reached, p < 0.005).Summary/Conclusion:In summary, we have identified TNFa as a critical, KIT D816V‐dependent, cytokine‐mediator that promotes clonal expansion of KIT D816V+ MC and may thereby be involved in clonal evolution and disease progression in SM.

PB2215 HOW TO PREDICT RESPONSE TO RUXOLITINIB IN PATIENTS WITH MYELOFIBROSIS

Background:Myelofibrosis (MF) is a classical myeloproliferative neoplasm characterized both in its primary and secondary form by splenomegaly, constitutional and disease‐related symptoms as well as by cytopenias. Aberrant constitutive activation of the JAK‐STAT pathway is core to its pathogenesis and the inhibitors of this pathway such as ruxolitinib, approved for MF treatment seven years ago, have been proven effective in a majority of patients.Aims:To describe ruxolitinib response and median survival in a group of patients diagnosed with MF in a single center and correlate it with the molecular profile, hematimetric data and previous myeloproliferative neoplasm (polycythemia vera (PV) or essential thrombocytosis (ET)).Methods:Of a total of one‐hundred twenty four patients diagnosed with MF in our center, thirty eight patients were treated with ruxolitinib between April 2012 and September 2018. Diagnosis of myelofibrosis was made based on bone marrow examination and according to the updated WHO criteria. Molecular study was carried out in peripheral blood for the mutation JAK2V617F as well as allele‐specific PCR for mutations type 1 and type 2 of exon 9 of calreticulin (CALR) gene, and exon 10 of myeloproliferative leukemia virus (MPL) gene. The prognostic risk stratification was carried out according to the International Prognostic Index (IPSS). All patients treated with ruxolitinib belonged to the intermediate group‐2 or were classified as high risk. Statistical analyses were performed in SPSS 15.0.Results:Average age of the group was 63 years (range 36‐88). 58% were males and 42% female. Average leukocyte, haemoglobin and platelet counts at diagnosis were 9,8x10e9/l (1.9‐62), 10.3 g/dl (6‐15.7) and 236x10e9/L (52‐789), respectively. 47% of patients had a previous diagnosis of another MPN (50% PV and 50% ET). JAK2V617F mutation was present in 70.3%, and CARL and MPL mutation in 12.5% and 2.6%, respectively. All patients responded to ruxolitinib although 39% finally lost this response, with a 13% evolution to acute leukemia, 40% of this group being subjected to allogeneic SCT. Currently, 73% of patients are alive. Six‐year overall survival of patients with JAK2V617F mutation was 80% compared to 60% of those with wild‐type mutational status, statistical significance not being reached. Patients with previous MPN also had greater six‐year overall survival (70%) than those with idiopathic MF (56%).Summary/Conclusion:Patients with MF with JAK2V617F mutation and previous MPN present a greater duration of response to ruxolitinib than others, probably due to greater inhibition of the preponderant pathogenetic mechanism and the more effective action of the drug on a more differentiated progenitor than in idiopathic MF, although broader studies are required to confirm these results.

PS1471 MYELOPROLIFERATIVE NEOPLASMS IN KOREAN CHILDREN AND YOUNG ADULTS

Background:Myeloproliferative neoplasms (MPNs) are a rare, heterogeneous group of clonal hematopoietic stem cell disorders, characterized by aberrant proliferation of one or more myeloid lineages leading to an overproduction of both mature and immature cells. Three major components of classical BCR‐ABL‐negative MPNs are polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (pMF). They may be transformed to either secondary MF (sMF) or secondary acute myeloid leukemia (sAML). In addition, they can have second cancers during follow up (FU). These classical MPNs primarily occur in middle and advanced age adults, and are exceptionally rare in pediatric age.Aims:We conducted an epidemiologic study to elucidate clinical course of MPNs in children and young adults under 30 years of age focusing on disease transformation as well as thromembolism and second cancers.Methods:We analyzing data from the Health Insurance Review and Assessment Service (HIRA) database which includes almost all hospital‐based patients’ information in Korea.Results:A total of 352 patients who were diagnosed as one of the three kinds of MPNs from Jan. 2008 to Dec. 2016 (242 patients for ET, 104 for PV, and 6 for pMF) were included. Six pMF patients were excluded from further analysis. The incidence was 0.148 per 100,000 for ET and 0.064 per 100,000 for PV. Among 242 ET patients, the male‐female ratio was 119 to 123, and median age at diagnosis was 22 years (range 13–29). Four ET patients (1.65%) underwent any transformation during the study period (median FU duration 49.5 months); ET→PV (i.e., initially diagnosed ET but changed to PV later; N = 2), and ET→sMF (N = 2). Among 104 PV patients, the male‐female ratio was 96 to 8, and median age at diagnosis was 24 years (range 11–29). No PV patients were transformed into sMF during the FU period (median 45.9 months). sAML did not develop in both ET and PV patients. Solid cancers occurred in 5 ET patients and 3 PV patients. Cumulative incidence of arterial and venous thromboembolism were 6.98% and 1.71% in ET, 16.69% and 4.77% in PV, respectively. Five‐year overall survival and transformation‐free survival (to PV, MF and cancer) were 98% and 96.12% in ET, 100% and 97.29% in PV, respectively.Summary/Conclusion:This is the first population‐based epidemiologic study in Korean children and young adults with MPNs. The incidence of MPNs is very low in this age group. ET is more common than PV, whereas pMF is very rare. Transformations of ET to PV or MF occurred in a small number of patients. Considering long latency to transformation in MPNs, continuous observation is needed. In addition, second solid tumors should also be carefully observed. Further research is necessary in this patient group, including studies involving other complications such as bleeding.

Thrombosis in the Philadelphia Chromosome-Negative Myeloproliferative Neoplasms.

The myeloproliferative neoplasms (MPNs) are clonal stem cell-derived diseases. This chapter focuses on the subcategory of Philadelphia (Ph) chromosome-negative classical MPNs, polycythemia vera (PV), essential thrombocythemia (ET), primary myelofibrosis (PMF). These MPNs are associated with both microvascular and macrovascular thrombosis, which may occur in the venous and arterial circulation. Erythrocytosis, leukocytosis, and increased JAK2V617F allele burden are known to be risk factors. In this chapter, we review the thrombotic and hemostatic manifestations of the Philadelphia (Ph) chromosome-negative classical MPNs, including the clinical manifestations, the pathophysiology, as well as management.

Direct Oral Anticoagulants As Secondary Prophylaxis in Classical Myeloproliferative Neoplasms

Introduction: Thrombosis is a major cause of morbidity and mortality in patients with classical myeloproliferative neoplasms (MPN), which include polycythemia vera, essential thrombocythemia and primary myelofibrosis. One third of patients with MPN suffer a thrombotic event, either arterial or venous. Despite this, there are no strong data to guide either the selection or duration of anticoagulants for MPN. Warfarin has been primarily used for long-term anticoagulation and is associated with a clear reduction in overall thrombotic events, however 20% of patients will have a recurrent thrombotic event despite ongoing warfarin anticoagulation, corresponding to a failure rate of 4-8% pt-yrs (AnnHematol 2015;94:911-918, Haematologica2008;93:372-380). The overall objective of this study was to evaluate recurrent thrombotic and major bleeding events in MPN-associated thrombosis treated with DOAC versus warfarin.Methods: The primary outcome was to compare the rate of thrombotic events in patients treated with DOAC versus warfarin for secondary thromboprophylaxis (treatment of first clot) among MPN patients. The secondary outcome compared the rate of bleeding events between the two groups. Electronic medical records for patients with a classical MPN diagnosis by PSVG criteria at the University of North Carolina Hospitals were queried to evaluate DOAC or warfarin medication orders between January 1, 2010 and May 31, 2017. Demographic laboratory data, concomitant medications, and incidence and severity of thrombotic or bleeding events were recorded for each MPN patient treated with a DOAC, warfarin, or aspirin. Descriptive statistics were used to characterize the population. Categorical variables were summarized as counts and percentages, while continuous variables were summarized as medians with first to third quartiles. The annual incidence of secondary thrombosis (ie: recurrent event) was calculated by dividing the number of events by the total number of patient-years (pt-yrs). 95% confidence intervals and comparisons were made using a Mid-P exact test. For all analyses, results were deemed significant if P<0.05.Results: We identified 38 total patients diagnosed with a classical MPN, who started either warfarin (n=33), a DOAC (n=4), or aspirin (n=1) for secondary thromboprophylaxis. Median age was 56 years (range 15-98), 40% were male, and 90% Caucasian. No significant differences in the baseline characteristics were observed (Table). For all patients, the initial thrombotic event occurred two years or less prior to the MPN diagnosis. Cytoreductive therapy with either hydroxyurea or anagrelide was used as additional secondary therapy in 28 patients. Patients who received cytoreductive therapy had similar rates of a second thrombus compared to those who did not. Six of the 34 patients who started on either warfarin or aspirin switched to a DOAC, where two of the six were switched after a bleeding event, and none experienced a second thrombus. Seventeen of the 33 patients who started on warfarin, experienced a clot while on therapy with total follow-up of 116.7 pt-yrs. Of those 17 patients, 4 switched to a DOAC and none experienced another thrombotic event at follow-up of 23.7 pt-yrs. The rate of secondary thrombus while on DOAC was 4.2 per 100 pt-yrs (95% CI: 0.2-20.8) compared with a warfarin rate of 14.6 per 100 pt-yrs (95% CI: 8.8-22.9), P=0.2. Eleven bleeding events occurred at a rate of 4.2 per 100 pt-yrs (95% CI: 0.2-20.8) on DOAC compared to 8.6 per 100 pt-yrs (95% CI: 4.4-15.3) on warfarin. This did not lead to a therapy switch in the one DOAC patient, but did lead to a switch in three of 10 warfarin patients (Table).Conclusion: These data suggest that DOACs are comparable to warfarin for preventing recurrent thrombotic events in MPN patients, with a similar risk of bleeding. There was a trend toward fewer thrombotic events in real world MPN-associated thrombosis treated with DOAC versus warfarin, though the small patient numbers do not allow definitive conclusions. Our data adds to the limited published experience using DOACs in MPN and strengthen rationale to pursue future prospective lines of inquiry that evaluate DOACs for secondary thromboprophylaxis in MPN patients. DisclosuresNo relevant conflicts of interest to declare.

Hippo Kinase Inactivation Contributes to Del(20q) Malignancies and Cooperates with JAK2-V617F to Promote Myelofibrosis in Mice

Recurring chromosome abnormalities are frequent events in cancer and are especially prevalent in hematologic neoplasms. Somatic heterozygous deletions on chromosome 20q are detected in a variety of hematopoietic malignancies including myelodysplastic syndrome (MDS), classical myeloproliferative neoplasm (MPN), MDS/MPN overlap disorders such as chronic myelomonocytic leukemia (CMML), and acute leukemias. Del(20q) is especially prevalent in MPN patients (~10-15%), where it is the most commonly detected cytogenetic abnormality associated with primary myelofibrosis (PMF) and post-polycythemia vera myelofibrosis (MF). This suggests that heterozygous loss of genes in the del(20q) common deleted region (CDR) may contribute to adverse MPN progression. Despite these observations, relatively few genes located within the CDR have been unambiguously implicated, highlighting a significant need for further investigation. To identify genes that may play an important role in the biology of del(20q)-associated malignancies we utilized a published gene expression dataset of bone-marrow derived CD34+ cells from MDS patients and healthy controls (Gerstung et al, 2015). Comparison of the patients harboring del(20q) to healthy controls revealed STK4 (encoding Hippo kinase MST1) to be the most significantly downregulated gene (mean: 3.5-fold) among those located within the chromosome 20q CDR. We therefore set out to assess the role of Hippo kinase inactivation in hematologic malignancy using conditional gene inactivation in mice.We found that complete inactivation of both Hippo kinases (Stk4 and Stk3) within the hematopoietic system using Vav1-Cre (Stk4-/-Stk3-/-) resulted in a lethal bone marrow failure (median survival: 7 weeks) associated with myelodysplastic features and frequent extramedullary hematopoiesis in the spleen. A single copy of Stk4 rescued the lethality due to bone marrow failure, however sub-haploinsufficient mice displayed thrombocytopenia with a trend towards mild anemia; phenotypes that closely resemble those observed in MDS patients with isolated del(20q). Both a reduced number of mature megakaryocytes and the presence of dysplastic megakaryocytes were apparent in bone marrow sections. Inducible Hippo kinase inactivation in adult mice using the Mx1-Cre system similarly recapitulated several phenotypic features of both MDS and MPN. In competitive bone marrow transplant assays we found that Stk4-/-Stk3-/- hematopoietic stem cells (HSC) completely lacked engraftment potential and failed to reconstitute normal hematopoiesis, revealing a potential role for Hippo kinase function in HSC homing and retention in the bone marrow. Heterozygous HSCs maintained relatively normal steady-state hematopoiesis in peripheral blood and bone marrow for up to 48 weeks in primary and secondary transplantations, although upon aging these mice were prone to development of thrombocytopenia with increased mean platelet volume.Given the high frequency of del(20q) in MPN, especially PMF, we asked whether heterozygous Hippo kinase inactivation may cooperate with the common driver mutation JAK2-V617F to accelerate disease progression. Using an HSC-enriched retroviral transduction/transplantation model in C57BL/6 recipient mice, we monitored MPN progression for 36 weeks in heterozygous Stk4+/-Stk3+/-, or control (Vav1-Cre-), cells with or without expression of JAK2-V617F. While both JAK2-V617F groups initially displayed a similar degree of polycythemia relative to controls, we found heterozygous Hippo kinase inactivation to promote accelerated disease progression towards lethal bone marrow fibrosis during the course of observation. Recipients in this group showed significantly reduced overall survival, which was associated with higher grade fibrosis in bone marrow, elevated peripheral granulocyte counts, enhanced splenomegaly, and increased frequencies of hematopoietic stem and progenitor populations in the spleen. Together, these findings implicate aberrant Hippo kinase loss-of-function in the pathogenesis of del(20q)-associated hematologic malignancies, and shed new light on the molecular events that contribute to adverse MPN progression. DisclosuresBejar:Genoptix: Consultancy; Modus Outcomes: Consultancy; Celgene: Consultancy, Honoraria; Takeda: Research Funding; Astex/Otsuka: Consultancy, Honoraria; AbbVie/Genentech: Consultancy, Honoraria; Foundation Medicine: Consultancy. Guan:Vivace: Equity Ownership.

Differential Impact of Interferon Alpha on JAK2V617F and Calr Mutated Hematopoietic Stem and Progenitor Cells in Classical MPN

Introduction:Classical BCR-ABL-negative myeloproliferative neoplasms (MPN) include Polycythemia Vera (PV), Essential Thrombocytemia (ET) and Primary Myelofibrosis (PMF). They are acquired clonal disorders of hematopoietic stem cells (HSC) leading to the hyperplasia of one or several myeloid lineages. They are due to three main recurrent mutations affecting the JAK/STAT signaling pathway: JAK2V617F and mutations in the calreticulin (CALR) and thrombopoietin receptor (MPL). Interferon alpha (IFNα) is the only drug that not only induces a hematological response in ET, PV and early MF, but also a significant molecular response on both JAK2V617F or CALR-mutated cells.Our broad aim was to understand the mechanism of action of IFNα. Previously, our group and others have shown that IFNα specifically targets JAK2V617F HSC in a chimeric JAK2V617F knock-in mouse model. In this study, we wanted to know how and how fast IFNα impacts the different mutated human hematopoietic compartments.Methods:A prospective study was performed with a cohort of 47 patients treated by IFNα for 3-5 years. The MPN disease distribution was 40% ET, 49% PV and 11% MF. This cohort included 33 JAK2V617F-mutated patients, 11 CALR-mutated patients (7 type 1/type 1-like and 4 type 2/type 2-like), 2 both JAK2V617F- and CALR-mutated patients and 1 MPLW515K-mutated patient. At 4-month intervals, the JAK2V617F or/and CALR mutation allele frequency was measured in mature cells (granulocytes, platelets). Simultaneously, the clonal architecture was also determined by studying the presence of the JAK2V617F or CALR mutations in colonies derived from the different hematopoietic stem and progenitor cell (HSPC) populations (CD90+CD34+CD38- HSC-enriched progenitors, CD90-CD34+CD38- immature progenitors and CD90- CD34+CD38+ committed progenitors).Results:After a median follow-up of 33 months, IFNα targets more efficiently and rapidly the HSPC particularly in HSC-enriched progenitors, than the mature blood cells in JAK2V617F patients (p<.05). Moreover, homozygous JAK2V617F clones responded more rapidly than heterozygous clones in all hematopoietic cell compartments showing that the intensity of JAK2V617F signaling is correlated with the efficacy of IFNα. This efficacy was slightly increased after a median follow-up of 51 months. In contrast, during a median follow-up of 33 months for CALR-mutated patients, IFNα targeted similarly the HSPC and the mature cells. Moreover, IFNα induced a slower response in targeting CALR-mutated HSPC than the JAK2V617F HSPC (p<.05) (see Figure). The role of associated mutations at diagnosis was also investigated in the IFNα-mediated HSPC molecular responses using a NGS targeted myeloid panel. In JAK2V617F-mutated patients, the number of associated mutations did not impact the HSPC molecular response. In contrast, in CALR-mutated patients, the only molecular responders were not associated with other mutations, although the lower number of cases should be expanded.Using Ba/F3-MPL cellular models and primary cells, we observed that JAK2V617F was more prone to sensitize to IFNα signaling (increased Phospho-STAT1 and IFN-stimulating genes (ISGs)) compared to controls or CALRdel52 mutated cells.Conclusion:Altogether, our results show that IFNα targets more efficiently the human JAK2V617F-HSPCthan the mature cells. Moreover, IFNα has a greater efficacy on JAK2V617F HSPC thanCALR-mutated HSPC. This former result was associated with a greater priming of the IFNα signaling by JAK2V617F than by CALRdel52. The molecular response was dependent not only on mutational status, but also on the presence of other associated mutations for the CALR-mutated HSPC. Patient data are currently incorporated into a mathematical model taking into account clonal architecture and associated mutations to develop an algorythm able to predict patient response. [Display omitted] DisclosuresKiladjian:Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; AOP Orphan: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Pregnancy Outcomes in Patients with Myeloproliferative Neoplasms: A Systematic Review and Meta-Analysis

▪IntroductionEssential thrombocythemia (ET), polycythemia vera (PV) and myelofibrosis (MF) are a group of hematopoietic stem cell-derived clonal disorders collectively known as the classical, Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs). Although MPN diagnoses are typically made in the sixth or seventh decade of life, approximately 20% of ET patients and 15% of PV patients are under the age of 40 years. Pregnancy with an MPN is associated with maternal thrombosis, hemorrhage and placental dysfunction leading to fetal growth restriction or loss. The aims of this systematic review were to determine the risk of maternal and fetal complications in pregnancy complicated by MPN and to quantify the benefit of commonly used interventions.MethodsA systematic search was conducted using MEDLINE (1946 to July 2018), EMBASE (1947 to July 2018), Cochrane Database of Systematic Reviews (2005 to July 2018), CCRCT (inception to June 2018), and Epub Ahead of Print & Other Non-Indexed Citations (inception to July 2018). Bibliographic references were reviewed for additional studies. There were no date or language restrictions and the review was registered with PROSPERO (CRD42018090680). Studies were included if they reported on maternal or fetal outcomes of pregnancy in patients with an MPN. Case reports and series including fewer than 10 patients were excluded. Duplicate reports were excluded, with only the most recent or most informative included. Data were extracted independently by two investigators (D.M. and S.K.).The primary outcome was live birth. Secondary outcomes included fetal complications (e.g. intrauterine growth restriction) and maternal complications (e.g. pre-eclampsia, thrombosis, hemorrhage). Study quality was assessed using the Newcastle-Ottawa Scale. Analyses were performed using Open Meta-Analyst version 10.12 and Review Manager version 5.3.ResultsThe search strategy resulted in 4191 records of which 22 met the inclusion criteria (Figure 1). The studies included a total of 779 women and 1226 pregnancies. Fifteen of the studies included patients with ET, 3 included patients with PV, and 4 included patients with any classical MPN. There were no studies of MF patients that met our inclusion criteria. Most of the studies were retrospective cohort studies (19) and 3 were prospective cohort studies.Among 1226 pregnancies, the live birth rate was 70%. Of 821 pregnancies with ET and 171 with PV, the live birth rate was 71% and 51%, respectively. The live birth rate was higher in patients with ET who received low dose aspirin during pregnancy than those managed with observation alone (OR 5.0; 95% CI 2.2 - 11.3; I226%; Figure 2). There was no further improvement with the addition of low molecular weight heparin (LMWH) to aspirin (OR 2.8; 95% CI 0.67 - 11.7; I20%). Interferon alpha (INF) during pregnancy was also associated with a higher live birth rate (OR 3.9; 95% CI 1.5 - 10.4; I22.5%; Figure 3). The presence of the JAK2 mutation resulted in a lower live birth rate (OR 0.58; 95% CI 0.4 - 0.9; I26%; Figure 4). Maternal events were unaffected by the addition of aspirin (OR 0.48; 95% CI 0.16 - 1.4; I20%) or INF (OR 0.1; 95% CI 0.01 - 1.5; I20%).Risk of bias assessment was performed using the Newcastle-Ottawa scale. Most studies included a representative cohort and follow up was generally adequate to at least 6 weeks postpartum. Only 3 studies included a control group.ConclusionsThe preliminary results of our systematic review determined that the live birth rate is lower in pregnant patients with MPN as compared to the general population. The chance of a successful pregnancy was higher in patients with ET than PV and the presence of the JAK2 mutation increased the risk of fetal loss. Patients who received low-dose aspirin during pregnancy had a 5-fold higher odds of a successful pregnancy than those managed with usual care and observation alone. Cytoreduction with INF improved the odds of live birth by nearly 4-fold. Maternal events were uncommon overall and no intervention was found to be beneficial. Our review is limited by generally small sample sizes and the retrospective nature of most studies. Additionally, given that the studies span up to 4 decades, our results may be affected by changing standards of care. Pregnancy in patients with MPN is uncommon and this is the only systematic review to determine the chance of successful pregnancy and quantify the benefit of commonly used interventions. [Display omitted] DisclosuresMaze:Novartis: Consultancy, Honoraria. Kazi:Shire: Other: Vonvendi was provided by Shire. Gupta:Novartis: Consultancy, Honoraria, Research Funding; Incyte: Research Funding.

Risk Factors for Secondary Cancer in a Case-Control Study on 1,259 Patients with Myeloproliferative Neoplasms

INTRODUCTIONThe incidence of secondary cancer (SC) in patients with myeloproliferative neoplasms (MPN) is high and comparable to that of thrombosis. However, the identification of patient subgroups that might be at increased susceptibility of developing SC has not been systematically addressed. We report here the results of an international case-control study (MPN-K) aimed at comparing the frequency of exposure to possible causes of SC in patients with classical MPN, polycythemia vera (PV), essential thrombocythemia (ET) and myelofibrosis (MF).METHODSThis European Leukaemia Network (ELN) study reports MPN patients from 28 sites of 5 European countries and Israel, diagnosed in the period from 2000 to 2016. Cases were MPN patients with concomitant diagnosis of a non-myeloid SC (n=15) or its presentation during the course of the disease (n=412). Controls were MPN patients cancer-free, matched to the paired case for sex, age (±5 years), date of MPN diagnosis (±5 years), and MPN disease duration (±6 years). A multivariable conditional logistic regression model was used to estimate the effect of selected variables on total SC risk and in different types of SC.RESULTSAmong 1,259 MPN patients, there were 427 cases and 832 matched controls. Cases presented melanoma (n=20; 4.7%), non-melanoma skin cancer (n=69; 16.2% - basal/squamous cell carcinoma), non-skin solid cancer (n=290; 67.9%) including breast, ovary/uterus, colorectal, upper gastrointestinal, liver/pancreas, lung, prostate/urinary, other and lymphoproliferative diseases (n=48; 11.2%) including multiple myeloma, chronic lymphocytic leukemia, low and high grade B- and T-lymphoma.At diagnosis, there were slightly more patients with PV among SC cases (n= 152; 35.6%) than controls (n=256; 30.8%), while conversely there were slightly less ET patients among cases (n=196; 45.9%) than controls (n=426; 51.2%). Cases and controls presented similar proportion of MF diagnosis (n=79 cases, 18.5% and 150 controls, 18.0%). Driver mutations (JAK2 V617, EXON-12, CALR, MPL), non-driver mutations and abnormal karyotype were equally represented in cases and controls. Other variables such as cardiovascular risk factors, exposure to cancerogens, family history of cancer and chronic inflammatory diseases were reported with similar frequency in cases and controls.After MPN diagnosis, exposure to first and other lines of treatments until the index event, with Phlebotomy (n=193; 15.3%), Hydroxyurea (n=814; 64.7%), Anagrelide (n=14; 1.1%), Interferon (n=30; 2.4%), Pipobroman (n=8; 0.6%), Busulphan (n=13; 1.0%), Ruxolitinib (n=11; 0.9%), was similar in the two groups except for aspirin that was used less frequently (p=0.043) in cases (n=320; 74.9%) compared to controls (n=664; 79.9%). In particular, the lower use of aspirin was circumscribed to non-skin solid tumors. A multivariable analysis was carried out in all patients and stratified by different type of tumors (Table). In non-skin solid cancers, the time to exposure of the MPN disease > 5 years (OR=2.95; 95% CI 1.54-5.66, p=0.001) and the PV phenotype (OR=2.40, 95% CI 1.15-5.01, p=0.020) were more burdened by the incidence of events than the reference ET group. No difference in SC risk was found for MF patients compared to patients with ET.Interestingly, the independent protective role of aspirin retained its statistical significance only in non-skin SC. In non-melanoma skin cancer, multivariable analysis revealed that the presence of JAK2 mutation was less associated with SC (OR=0.32, 95% CI 0.13-0.81, p=0.016) and confirmed that exposure to HU and other cytotoxic agents was associated with a significantly higher risk of SC (OR=6.00, 95% CI 1.23-29.28, p=0.027 and OR=9.80, 95% CI 1.24-77.78, p=0.031, respectively). This finding was not seen in non-skin SC and in lymphoma.CONCLUSIONThe considered clinical and biological features, at MPN diagnosis, were not different in cases with SC and controls. During the course of the disease, three factors significantly and independently affected the risk of SC in these MPN patients: 1) patients with PV had a 77% higher risk than those with ET, 2) patients with MPN duration of more than 5 years had a twice higher risk than those with lower duration, 3) for the first time, we documented that in non-skin solid cancers, aspirin treatment reduced SC risk of 38%. Exposure to HU and other cytoreductive drugs was confirmed as a risk factor for non-melanoma skin cancer. [Display omitted] DisclosuresPalandri:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Marchetti:Gilead: Consultancy; takeda: Speakers Bureau; amgen: Speakers Bureau; janssen: Speakers Bureau. Griesshammer:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Investigating the Role of the Gut Microbiome in the Inflammatory State of Myeloproliferative Neoplasms

The human microbiome is composed of trillions of micro-organisms living in symbiosis with the human body. The interest in the microbiome and the clinical impact of its disruption (dysbiosis) has grown exponentially in the past years, especially in the oncology field. Microbiota play an instructive role in chronic inflammatory disorders and determine response to checkpoint inhibitors cancers, such as melanoma. Increased inflammation in myeloproliferative neoplasms (MPN) drive many of the symptoms associated with this disease and inflammation also likely plays an important role as a driver of the disease. We hypothesized that the microbiome may be dysregulated in MPN which could contribute to the increased inflammatory cytokines seen in this disease and that the microbiome could also potentially impact symptom burden.We compared the gut microbiota of 25 patients with classical MPN, essential thrombocythemia (ET), polycythemia vera (PV) and primary and secondary myelofibrosis (MF) to that of 25 normal controls. Whenever possible, co-inhabiting adults such as a spouse were used as normal controls. Exclusion criteria were acute illness and antibiotics treatment for three months preceding the study. Each participant collected three stool specimens in the course of one week and a subset of the group (n=20) had peripheral blood drawn. The stool microbiome was analyzed using 16S rRNA sequencing and plasma inflammatory cytokines (TNFα, IL-6, IL-8, IL-17a, IL-10, IFNγ, IFNa2, IL-22, IL1-β, GRO, IP-10) were measured using Luminex multiplex analysis. Participants also completed an intake survey which included symptom burden (MPN-SAF TSS) and dietary intake.Characteristics of our MPN patient cohort and normal controls are shown in Table 1. Plasma levels of TNFα and IP-10 were significantly higher in the MPN group versus normal controls (respectively p=0.013 and p=0.0050). We divided the group into those with high (MPN-SAF > 20) and low (MPN-SAF ≤ 20) symptom burden, 7 (28%) patients had high symptom burden affecting considerably their quality of life. Fatigue and early satiety were the most common complaints. GRO (CXCL1) was significantly lower in MPN patients MPN patients with a lower symptom burden (p=0.0287) as compared to those with a high symptom burden.The 16S rRNA gene sequencing did not reveal a significant difference between MPN patients and their healthy counterparts (PERMANOVA, p = 0.83), a large amount of variance in the microbiome data was explained by the individual (PERMANOVA, p= 0.0001), in concordance with other studies suggesting that the microbiome is highly individualistic. To determine whether certain taxa are differentially represented in MPN patients as compared to normal controls, a SIMPER test was used. Prevotellaceae, a family of bacteria implicated in chronic inflammatory conditions, was 20% higher in MPN patients than in normal controls.To test which cytokines explained the most variance in the microbiome data, a distance-based linear model was used (DistLM). TNFα and IL-17a, taken alone, explain 18.7% and 14.5% respectively. The microbiome of patients with a high symptom burden was not significantly different from MPN patients with low symptom burden. We did find a significant difference between the microbiomes of patients treated with Ruxolitinib versus Hydroxyurea.Taken together, this pilot study suggests that inflammation associated with MPN may be driving changes in the microbiome at a finer level, undetected when comparing broad microbial diversity metrics between health and disease. It is still not clear whether the inflammation first modulates the microbiome or whether the gut microbiota triggers the inflammatory signals driving the disease. A larger number of subjects may help answer these questions. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Myeloproliferative Neoplasms in Asia, Including Middle East, Turkey, and Algeria: Epidemiological Indices and Treatment Practice Patterns from the Multinational, Multicenter, Observational MERGE Registry

BackgroundThe Philadelphia chromosome−negative classical myeloproliferative neoplasms ([MPNs], including essential thrombocythemia [ET], polycythemia vera [PV], and myelofibrosis [MF]), are generally associated with a substantial disease burden, often leading to a reduced quality of life (QOL) and shortened survival in many patients (pts). There has been a lack of estimates for the incidence/prevalence and treatment patterns of MPNs in many regions of the world, including countries from South Asia, Asia Pacific, Middle East, and Turkey. Hence, there is a need to establish databases like registries, which would provide information on the “real-world” data in these regions. The MERGE registry was initiated with an objective to collect data on the epidemiological indices of MPNs and existing treatment patterns in Asia, including Middle East, Turkey, and Algeria. This primary descriptive analysis from the MERGE registry was performed to estimate the incidence/prevalence, natural disease course, and treatment patterns of MPNs in these countries.MethodsMERGE is a multinational, multicenter, nonintervention study that included adult pts with MPNs, who were diagnosed according to World Health Organization 2008 criteria. The data were collected retrospectively (since diagnosis) and prospectively after enrollment in the study. Disease assessments were scheduled every 6 months up to 5 visits, with a minimum of 2 years of follow-up. Pts who participated or were participating in a randomized clinical trial were allowed. Data were analyzed descriptively.ResultsIn total, 884 MPN pts (ET=373, PV=301, MF=169, and unclassified=41) were included in the full analysis data set. The median age was 58 years (range, 47-66 years; younger compared to other regions) and 50% pts were males. Baseline pt characteristics by MPN subtype are summarized in Table 1. About 57% of pts were diagnosed by incidental finding of abnormal blood results followed by bone marrow evaluation. In these countries, the prevalence and incidence of MPNs are estimated to be 57-81 and 12-15 per 100.000 hospital-patients per year over the last 4 years, respectively.As assessed by MPN Symptom Assessment Form (MPNSAF), 92% of the pts reported at least 1 symptom. At baseline, fatigue was the most common symptom in all 3 MPN subtypes (71% MPN; 78% MF; 71% ET; and 68% PV). Inactivity (64%), early satiety (61%), abdominal discomfort (57%), bone pain (56%), weight loss (52%), night sweats (46%), and fever (29%) were more common in MF; whereas, itching in PV pts (50%). MF pts had the highest total symptom score at baseline (mean [SD], 23.5 [17.47]) as compared to ET (mean [SD], 14.6 [14.26]) and PV pts (mean [SD], 16.6 [14.84]). Overall, 64% of pts had ECOG performance status of 0 and 26% had ECOG 1.During study period, the most common nonpharmacological intervention was red cell transfusion in MF and ET pts, and phlebotomy in PV pts. Splenectomy (n=2) and stem cell transplantation (n=4) were rarely employed (6 MF pts). Hydroxyurea (HU) was the most common first-line therapy in all 3 MPN subtypes (overall, 54%; PV, 61%; ET, 54%; and MF, 39%), followed by aspirin. Other common first-line therapies were anagrelide (10%) and interferon (9%) in ET pts, antineoplastic (6%) and clopidogrel (6%) in PV, and JAK2 inhibitors in MF pts (15%). More than 75% of the induction therapies were monotherapies, with less than 3% of pts receiving 3 or more drug combinations as primary treatment. Patients with MF often received monotherapy (81%), than the other patients with MPN. Median duration of first-line therapy was about 6 months (95% CI, 1-21 months), and first-line therapy discontinuation rates of 35%, 36%, and 30% were noted in ET, PV and MF pts, respectively. Interferon was used in 8% of in the second-line setting. JAK2 inhibitors were more frequently (14%-17%) used in the second-and third-line settings.ConclusionsThe prevalence and incidence of MPNs in countries from Asia Pacific were derived using the number of pts visiting the corresponding hospitals. Thus, the resulting incidence and prevalence reported here are not directly comparable with the country-based prevalence/incidence and may overestimate the actual values. At baseline, pts with MPNs had significant disease burden. The most common first-line therapy was HU, though discontinuation rates of first-line therapies were high, and JAK2 inhibitors were mostly used in the second-line/third-line settings. DisclosuresYassin:Novartis: Research Funding. Taher:La Jolla Pharmaceutical: Research Funding; Ionis Pharmaceuticals: Consultancy; Celgene Corp.: Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Protagonist Therapeutics: Consultancy. Kim:Novartis Korea: Honoraria. Rippin:Employee of IQVIA - doing consultancy for Novartis: Consultancy. Sadek:Novartis Pharmaceutical Corporation: Employment. Siddiqui:Novartis Pharma AG: Employment, Equity Ownership. Wong:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Abnormal Distribution and Function of NK Cells Subsets May Lead to Impaired Tumor Surveillance in a JAK2V617F Myeloproliferative Neoplasm Model

Background: The JAK2V617F mutation is the most common molecular abnormality present in Philadelphia chromosome-negative Classical Myeloproliferative Neoplasms (Ph-neg MPNs), present in approximately 95% of patients with Polycythemia Vera and in almost 50% of patients with primary myelofibrosis and essential thrombocythemia. Besides the genetic mutations, different cells in the bone marrow can modulate the microenvironment and contribute to disease initiation and maintenance. Natural killer (NK) cells are part of innate immunity and are divided into subsets, according the expression of CD27 and CD11b. The immature NK cells, CD27-CD11b- (tolerant), CD27+CD11b-, presenting less cytotoxicity, while the mature NK cells, CD27+CD11b+ and CD27-CD11b+ (cytotoxic), have a great cytotoxic function. Considering that the role of NK cells in Ph-neg MPNs is currently unclear, our hypothesis is that a defect of the NK cells may favor HSC malignant transformation and contribute to MPN development. Aim: We aimed to study their distribution and cytotoxic function in murine primary cells from a MPN transgenic model. Methods: NK cells were quantified by flow cytometry from splenocytes of a pre-established conditional vavCre knockin Jak2V617F (Jak2VF) murine model. Polycythemia and splenomegaly were confirmed in Jak2 wt/V617F vavCre+ (Jak2VF) as compared to Jak2 wt/wt vavCre+ (Jak2WT) control animals. Mice (n= 4 per group) were euthanized between 10-16 weeks of age. For immunophenotyping, spleen was isolated, submitted to red cell lysis, and stained with fluorescence-conjugated antibodies against Ter119, CD19, CD4, CD8 CD3, NK1.1, CD27, CD11b, CD69 and CD107a. All the stainings were performed at 4°C for 20 minutes and acquisition of at least ten thousands events per tube was performed in a FACSCanto™II flow cytometer. For the activation and degranulation assays, splenocytes were cultivated and stimulated with PMA (2.5ug/mL) and ionomicyn (0.7ug/mL) for 3 hours and then submitted to the analysis of CD69and CD107a expression, respectively. The cytotoxicity assay was performed by a co-culture of sorted NK cells with YAC-1 cells previously marked with an impermeable cell tracker, for 3 hours. Then, the target cell death percentage was determined by 7-AAD detection. Results: The analysis of the degranulation marker CD107a in activated NK cells (CD69+) showed that, when compared with the Jak2WT group, the Jak2VF mice presented a decreased frequency of CD107a+ NK cells (87.2% vs 74.1% p=.02). Besides, the ability of Jak2VF NK cells to kill the target cells was reduced when compared to the Jak2WT group (80.1%±17.4 vs 65.5%±8.7 at the 5:1 NK:target cell ratio and 84.9%±11.9 vs 75.3%±0.1 at the 10:1 NK:target cell ratio). The maturation profile showed that, when compared to Jak2WT mice, the frequency of immature NK cells was 4.2-fold increase in Jak2VF animals (8% vs 33% p=.009), and the percentage of these cells that expressed the degranulation marker CD107a was reduced when compared with the Jak2WT group (55.5% vs 42.7% p=.02). In agreement, the frequency of mature NK cells was decreased in Jak2-mutated mice (92% vs 67% p=.009) as compared to controls. Among the mature NK subpopulations, CD107+ cells were lower numbered in Jak2VF mice as compared to Jak2WT cells (94.3% vs 88.9% p=.005). We also observed a differential profile of functional NK subsets between Jak2WT and Jak2VF NK cells. There was an increase of CD27-CD11b- and CD27+CD11b- NK cells in Jak2-mutated mice (5.6% vs 18.3% p=.007 and 2.1% vs 14.6% p=.01, respectively). On the other hand, the percentage of CD27-CD11b+ NK cells in Jak2VF mice was lower than in Jak2WT mice (78.1% vs 49.9% p=.01). In summary, when compared to controls, Jak2-mutated mice presented a reduction in the frequency of NK cells able to release their lytic granules, suggesting a lower cytotoxic function. The reduction of cytotoxicity in Jak2VF NK cells may be explained by two factors: (1) the augment of immature tolerant NK cells, and (2) the reduction of cytotoxicity of the mature subset (CD27-CD11b+). To date, although the functional and maturation subsets of NK cells have been studied in solid tumors, they have not been previously associated with MPNs. Conclusion: Considering that mature and functional NK cells play a critical role in tumor surveillance, it is plausible that an impair of their distribution and function can favor stem cell-derived diseases like Ph-neg MPNs DisclosuresNo relevant conflicts of interest to declare.

Impact of Myeloproliferative Neoplasms (MPNs) on Health-Related Quality of Life (HRQOL) and Medical Resource Utilization: Results from the MERGE Registry

BackgroundThe Philadelphia chromosome−negative classical MPNs (myelofibrosis [MF], polycythemia vera [PV], and essential thrombocythemia [ET]) are associated with a pronounced symptom burden, including fatigue, night sweats, itching, and inactivity that may affect patients' HRQOL. There is a limited real-world evidence from many of the Asian countries, including Middle East, regarding the impact of MPNs on HRQOL, or the economic burden associated with these diseases. MERGE is a multinational, multicenter, nonintervention study conducted in adult patients with MPNs in Asia, including Middle East, Turkey, and Algeria. The present analysis evaluated the impact of MPNs on HRQOL of patients from MERGE and explored the association of HRQOL with the clinical outcomes and resource utilization.MethodThe MERGE registry included patients with MPN diagnosed as per the World Health Organization 2008 criteria. Patients were planned to be followed up for 2 years (5 visits over the course of study). MPN Symptom Assessment Form Total Symptom Score (MPNSAF TSS) was administered during the routine biannual follow-up visits to assess the HRQOL. MPNSAF TSS score was calculated only for patients who completed at least 6 of the 10 items on the MPNSAF TSS questionnaire. The level of inter-rater agreement between physicians and patients on the proportion of symptomatic patients was assessed through Cohen's Kappa coefficient.Further, an ANCOVA (Analysis of covariance) model was applied to estimate the influence of the baseline variables (age, sex, weight, height, family history of MPNs, comorbidities, time to initial MPNs diagnosis, type of MPN initial diagnosis, baseline hemoglobin and platelet count, Eastern Cooperative Oncology Group Performance Status [ECOG PS], and time since diagnosis to treatment initiation) on the TSS score. Variables with univariate P-value < 0.20 were included in the multivariate model.Furthermore, medical resource utilization was assessed by evaluating the inpatient and outpatient visits, hospice care, emergency room visits, and day care.ResultsOf the 884 eligible patients with MPNs, 169 had MF, 301 had PV, 373 had ET, and 41 had unclassified MPN. During the study, 64% of patients received hydroxyurea, 15% interferon, 15% JAK inhibitors, and 10% anagrelide either alone or in combination. At baseline, the proportion of patients presenting at least 1 of the symptoms was higher in the MF group (96.4%), compared to the total MPN patients (91.8%). In addition, the TSS (mean [SD]) at baseline was highest in the patients with MF (23.5 [17.47]) as compared to patients with ET (14.6 [14.26]) and PV (16.6 [14.84]). During the study duration and follow-up, the TSS remained approximately constant at subsequent visits.Physicians reported a lower proportion of symptomatic patients than the proportion self-reported by patients, although, there was better agreement between physicians and patients for pruritus and night sweats (Kappa, 0.61-0.80) (Table 1) than for other symptoms (Kappa, 0.41-0.60). Across MPN subtypes, inter-rater agreement was lowest for patients with MF compared to patients with ET or PV.In a multivariate adjusted mixed effect regression model, female gender, type of MPN (MF), presence of comorbidities, lower baseline hemoglobin were independently and positively associated with the symptom score values.Overall, 24.3% of the patients had at least 1 inpatient visit, with a mean duration of 11.1 days. Outpatient visits were the most commonly observed healthcare resource used (95.5%), without remarkable change during the follow-up period. Patients with ET had a lower mean number of inpatient visits (mean [SD]: 0.9 [0.77] days), and patients with MF had more outpatient visits (mean [SD]: 5.2 [3.17] visit) on an average, compared to the entire MPN group.ConclusionDespite being on treatment, patients with MPN in MERGE had substantial symptom burden, which did not change over the course of the study. A discordance between physician and patient perception of symptom assessment was seen in this study, indicating that in addition to spleen and hematological investigations, a more systematic assessment such as the use of MPNSAF TSS could help to better evaluate patients' symptoms and understand the disease and its treatment burden. [Display omitted] DisclosuresTaher:Celgene Corp.: Research Funding; Ionis Pharmaceuticals: Consultancy; Protagonist Therapeutics: Consultancy; La Jolla Pharmaceutical: Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Yassin:Novartis: Research Funding. Rippin:Employee of IQVIA - doing consultancy for Novartis: Consultancy. Sadek:Novartis Pharmaceutical Corporation: Employment. Siddiqui:Novartis Pharma AG: Employment, Equity Ownership. Wong:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Myeloproliferative neoplasms (MPNs) - Part 2: A nursing guide to managing the symptom burden of MPNs.

Myeloproliferative neoplasms (MPNs) are rare, yet potentially life-threatening, disorders caused by overproliferation of bone marrow stem cells. The symptom burden experienced by patients with the BCR-ABL1-negative MPNs (also referred to as the classical MPNs, i.e., essential thrombocythemia [ET], polycythemia vera [PV] and myelofibrosis [MF]) can be significant and can negatively impact quality of life (QOL). Since patients with these MPNs can live for several years, thereby requiring long-term treatment and follow-up, nurses play an essential role in communicating with these patients, assessing their symptoms, and educating them on treatments and self-management strategies that can reduce their symptom burden. This article, which is the second of a twopart series, was developed to provide nurses and other healthcare professionals with practical guidance for managing the symptom burden associated with the classical MPNs in order to help enhance their patients' overall health and QOL.

Myeloproliferative neoplasms (MPNs) - Part 1: An overview of the diagnosis and treatment of the "classical" MPNs.

Myeloproliferative neoplasms (MPNs) are rare, yet potentially life-threatening, disorders caused by overproliferation of bone marrow stem cells. The symptom burden experienced by patients with the BCR-ABL1-negative MPNs (also referred to as the classical MPNs, i.e., essential thrombocythemia [ET], polycythemia vera [PV] and myelofibrosis [MF]) can be significant and can negatively impact quality of life (QOL). Since patients with these MPNs can live for several years, thereby requiring long-term treatment and follow-up, nurses play an essential role in communicating with these patients, assessing their symptoms, and educating them on treatments and self-management strategies that can reduce their symptom burden. This article, which is the first of a two-part series, was developed to provide nurses and other healthcare professionals with a review of the diagnosis and treatment of the most common classical MPNs. The second article in this series (also available in this issue) will provide nurses with practical guidance for managing the symptom burden associated with MPNs in order to help enhance the overall health and well-being of patients living with these disorders.

Precision immunotherapy, mutational landscape, and emerging tools to optimize clinical outcomes in patients with classical myeloproliferative neoplasms.

Following the 47th American Society of Hematology Meeting in 2005, the late John Goldman and Tariq Mughal commenced a conference, the 1st Post-ASH Workshop, which brought together clinicians and scientists, to accelerate the adoption of new therapies for patients with myeloproliferative neoplasms (MPNs). The concept began with recognition of the CML success story following imatinib therapy, the discovery of JAK2V617F , and the demonstration that BCR-ABL1-negative MPNs are driven by abnormal JAK2 activation. This review is based on the presentations and deliberations at the XIIth Post-ASH Workshop on BCR-ABL1 positive and negative MPNs that took place on December 12 to 13, 2017, in Atlanta, Georgia, immediately following the 59th American Society of Hematology Meeting. We have selected some of the translational research and clinical topics, rather than an account of the proceedings. We discuss the role of immunotherapy in MPNs and the impact of the mutational landscape on TKI treatment in CML. We also consider how we might reduce TKI cardiovascular side effects, the potential role of nutrition as adjunctive nonpharmacologic intervention to reduce chronic inflammation in MPNs, and novel investigational therapies for MPNs.

Major Changes to the 2017 Revision of the World Health Organization Classification of Myeloproliferative Neoplasms

The World Health Organization (WHO) Classification of Tumors of Haematopoietic and Lymphoid Tissues was recently published in a revised fourth edition. The categories of myeloproliferative neoplasms (MPNs) have not significantly changed since the 2008 fourth edition of the classification; however, newly discovered mutations including CALR and CSF3R and improved characterizations and standardizations of morphological features of some entities, particularly BCR-ABL1-negative MPNs, have impacted the diagnostic criteria of disease entities, increasing the reliability and reproducibility of diagnoses. The 2017 revised edition attempts to incorporate new clinical, prognostic, morphologic, and genetic data that have emerged since the last edition. This article reviews the major changes in the classification and their rationale for MPN classification within the revised 2017 WHO system. Keywords: Essential thrombocythemia; Myeloproliferative disorders; Polycythemia vera; Primary myelofibrosis; World Health Organization

Ruxolitinib Rechallenge Can Improve Constitutional Symptoms and Splenomegaly in Patients With Myelofibrosis: A Case Series

IntroductionMyelofibrosis (MF) is one of the classic myeloproliferative neoplasms and can occur de novo or following transformation from polycythemia vera (PPV MF) or essential thrombocythemia (PET MF). It can be associated with constitutional symptoms and splenomegaly, both of which can negatively impact quality of life. The only curative option for MF is allogeneic stem cell transplantation. Studies have shown that JAK2 inhibitors such as ruxolitinib are effective in reducing both splenomegaly and symptom burden. Although there is no approved treatment for patients who progress on ruxolitinib, anecdotal evidence suggests patients may respond to a re-challenge of ruxolitinib after drug cessation. Patients and MethodsWe conducted a multi-institutional, retrospective case series to study patients who were re-challenged with ruxolitinib after inadequate response to or loss of response with an initial treatment course. Thirteen patients were identified. Six patients had primary MF, 3 patients had PPV MF, and 4 patients had PET MF. Ten patients were JAK2-positive, 2 were CALR-positive, and 1 patient had neither mutation. Nine patients received 1 ruxolitinib re-challenge, and 4 received 2 re-challenges. Response was defined as improvement in constitutional symptoms and/or reduction in spleen size. ResultsDuring the primary treatment course with ruxolitinib, there was improvement in constitutional symptoms and reduction in spleen size in 92% and 85% of patients, respectively. Following cessation of ruxolitinib, all patients received a first re-challenge course with improvement in symptoms and splenomegaly in 92% and 69%, respectively. Of the 4 patients who received a second re-challenge course of ruxolitinib, all had improvements in spleen size and constitutional symptoms. Six patients have continued on a first or second ruxolitinib re-challenge course with good response. ConclusionOur study demonstrates that re-exposure to ruxolitinib following a period of treatment cessation in patients with MF can lead to durable responses with regards to both splenomegaly and symptom burden.

Clinical Analysis of Driver Mutations in Patients with Ph Negative Myeloproliferative Neoplasms

To explore the relationship between driver mutations and clinical characteristics in patients with Philadelphia chromosome (Ph) negative myeloproliferative neoplasms (MPN), so as to provide evidence for diagno-sis and treatment of the disease. The clinical data of 410 patients with classic Ph negative MPN including 150 cases of polycythemia vera (PV), 188 cases of essential thrombocythemia (ET) and 72 cases of primary myelofibrosis (PMF) from January 2013 to December 2016 in Fujian Medical University Union Hospital were retrospectively analyzed. The PCR or DNA sequencing were used for JAK2 V617F, JAK2 exon12, CALR and MPL W515L/K mutation analyses, and follow-up information on patients was updated by direct phone call or follow-up in outpatient. Among the 410 patients with Ph negative MPN, 136 (33.2%) cases were asymptomatic at diagnosis. 389 cases were sequenced and JAK2 V617F was detected in 87.1% (122/140) of PV, 64.1% (118/184) of ET, 64.6% (42/65) of PMF; JAK2 exon 12 mutation in 1 case of PV; MPL W515L/K mutation in 1 case of ET and PMF, respectively; CALR mutation in 18(9.8%) cases of ET and 5 (7.7%) cases of PMF. JAK2 V617F mutated PV patients ocourred in older age: the white blood cell count, platelet count and incidence of splenomegaly were higher than JAK2-negative PV cases(P<0.05). Compared with JAK2 V617F mutated ET patients, CALR mutated ET cases displayed younger age, lower leukocyte count, higher platelet count and lower incidence of thrombosis; JAK2-negative ET cases had younger age, lower leukocyte count, lower hemoglobin level, higher platelet count and lower incidence of thrombosis(P<0.05). The incidence of splenomegaly in JAK2 V617F or CALR mutated PMF patients was both higher than that in JAK2-negative PMF cases, but the incidence of leukemia transformation in JAK2-negative PMF patients was higher than that in JAK2 V617F mutated cases (P<0.05). The types of driver mutations are closely related with the clinical features and prognosis in Ph- negative MPN patients.