ALBERT

Description: BACKGROUND: Symptom burden in essential thrombocythemia (ET) and polycythemia vera (PV) is severe even among individuals with low risk disease (Blood 2012. 12;123(24):3803-10). New therapies exist which alleviate the severe symptom burden and reduce splenomegaly in ET and PV patients (N Engl J Med 2015; 372:426-435). This analysis is the first to date to evaluate thresholds at which symptom-based treatment can be considered for ET and PV patients who are intolerant or resistant to hydroxyurea (HU). METHODS: Patient demographics, symptom burden, and disease traits were collected from ET and PV patients at a single time point during therapy. The MPN-10 total symptom score (TSS, JCO 2012;30(33)4098-103) was utilized to assess symptom burden. Symptom criteria models were determined as previously described among a population of MF patients (Scherber et. al. EHA 2016: a2250). Cutoffs were then evaluated in a cohort of ET and PV patients to assess for utility as a symptom model among this population. RESULTS: Demographics and symptom burden: 838 PV and 867 ET patients with previous hydroxyurea therapy were included in this analysis. Patients were of mean age (54.9 years ET, 64.0 years PV) and gender (69.2% female ET, 55.7% female). Mean disease duration was 6.0 years for ET and 7.3 years for PV.Among ET and PV patients, 15.0% and 24.2% had prior thrombosis respectively. In evaluating prognostic risk, ET patients tended to be low (45.5%) or intermediate risk (42.9%) with only a minority of patient meeting criteria forhigh risk disease (11.6%). Laboratory findings: ET patients had a mean platelet value of 598.7x 109/L(SD=283.4). Among PV patients, mean hematocrit was 45.8% (SD=8.1) and 42.6% of patients had a hematocrit of greater than 45%. White blood cell count was normal between the two groups (ET mean 8.3 x 109/L, PV mean 9.0 x 109/L). Symptoms: Mean worst symptom severity was 6.4 out of 10 (SD=2.7). Among ET patients, worst symptom was most frequently fatigue (32.7%, mean 5.0/10, SD=3.1, overall prevalence 88%) followed by night sweats (13.6%, mean 2.0/10, SD=3.0, overall prevalence 53%) and concentration difficulties (8.6%, mean 3.1/10, SD=3.0, overall prevalence 68%). For PV, worst individual symptom items were most frequently fatigue (29.2%, mean 5.2/10, SD=3.0, overall prevalence 91%), pruritus (14.1%, mean 3.2/10, SD=3.2, overall prevalence 69%), and night sweats (12.8%, mean 2.5/10, SD=3.0, overall prevalence 57%). Cutoff Scoring: 47.0% of ET patients fit criteria for TSSgreater than to equal to 20; 59.0%% had a single itemgreater than 5; and 45.7% had both a TSS greater than or equal to 20 and a single item greater than 5. Among PV participants, 54.5% had aTSS greater than to equal to 20; 66.1% had a single itemgreater than 5; and 51.5% had both a TSS greater than or equal to 20 and a single item greater than 5. Each scoring method was significantly associated with individual item scores (Table 1). Prognostic scoring was not significantly associated with any of the symptom cutoffs evaluated. Correlations: Among ET patients, a prior history of thrombosis was significantly associated with having a worst symptom item greater than 5 (p=0.043). ET patients with lower hemoglobin were significantly more likely to meet criteria for a MPN-10 score greater than or equal to 20 or to meet combined criteria for a MPN-10 greater than or equal to 20 and single worst item greater than 5 (for both p=0.01 or less). For PV, lower hematocrit levels were significantly associated with having an individual worst symptom score of greater than 5 (44.9% versus 46.7%, p=0.0376). CONCLUSION: Assessment of ET and PV symptoms, now measurable through standardized and practical instruments such as the MPN-10, is an integral part of determining therapeutic impact of newer therapies in both clinical practice and trial settings. In our modeling, patients with severe symptom burden profiles are well represented by utilizing cutoff criteria including aworst individual symptom item of greater than 5 out of 10, an MPN-10 score of greater than or equal to 20, or combined criteria of both cutoffs. These cutoffs can be considered when determiningwhich HU intolerant or resistant patients would most benefit fromsymptom orientedtreatment. Disclosures Kiladjian: AOP Orphan: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Research Funding. Schouten:Novartis: Consultancy; Sanofi: Consultancy. Etienne:BMS: Speakers Bureau; ARIAD: Speakers Bureau; Pfizer: Speakers Bureau; novartis: Consultancy, Speakers Bureau. Harrison:Incyte Corporation: Honoraria, Speakers Bureau; Shire: Honoraria, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Baxaltra: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau. Radia:Pfizer: Honoraria; Novartis: Honoraria. Cervantes:AOP Orphan: Membership on an entity's Board of Directors or advisory committees; Baxalta: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Mesa:Promedior: Research Funding; Celgene: Research Funding; CTI: Research Funding; Gilead: Research Funding; Incyte: Research Funding; Galena: Consultancy; Ariad: Consultancy; Novartis: Consultancy.

Description: Abstract 2818 Background: Pegylated interferon alpha-2a (Peg INF2a) has been demonstrated to be active therapy for high-risk essential thrombocythemia (ET) and polycythemia vera (PV), as well as treatment for early myelofibrosis (MF). We retrospectively analyzed the outcomes of Peg INF2a therapy in MPN patients treated outside the constraints of a clinical trial in the USA and EU. Methods: Clinical records of MPN patients treated at the participating centers, receiving Peg INF2a outside of the context of a clinical trial, were analyzed for response (ET and PV by ELN criteria; MF by EUNMET and IWG-MRT criteria), toxicity, and duration of response. Results: Patients: 115 patients were identified (54 PV (47%), 44 ET (38%), 17 MF (15%)) with a median age at diagnosis (48) and gender distribution (59% females) typical for the disorders. The patients had been diagnosed with the MPN a median of 44 months (0.0–312 months) prior to initiation of the Peg IFN2a and 64% harbored the JAK2-V617F mutation. The majority of patients (81%) had received at least one prior cytoreductive therapy for their disease (73 hydroxyurea, 39 anagrelide, 37 aspirin, 21 prior interferon (non pegylated), 3 phlebotomy alone). Therapy: Median starting dose of Peg INF2a was 45 micrograms/week (range: 22.5–180) with peak starting doses ranging from 30 to 300 micrograms/week. A total of 84 patients (73%) remain on Peg IFN2a with median duration of treatment of 17 months (range: 1.0–92). Toxicity: Overall the Peg INF2a was well tolerated. Hematological toxicity was Gr 3 or lower. There were 6 cases with anemia (5%), 10 with thrombocytopenia (9%) and 8 had leukopenia (7%). Most common non-hematologic toxicities were Gr 1–3 fatigue in 27 (23%), Gr 1 LFT elevation in 6 (5%), Gr 2–3 skin/allergic reaction in 6 (5%), Gr 1–2 nausea in 5 (4%), and Gr 2 mood disorder in 5 (4%) patients. Twenty patients (17%) discontinued therapy secondary to toxicity. Response: ET-PV: By ELN criteria, 30 PV patients achieved CR (55%), 17 achieved PR (31%), 4 achieved NR (7%), and 3 patients (5%) were lost to follow up or were too early to evaluate for response. In ET, the responses were CR in 27 (61%), PR in 7 (16%), NR in 4 (9%), and 6 patients (14%) were lost to follow up or were too early to evaluate for response. MF: The responses by IWG criteria were 1 CR (6%), 2 PR (12%), 2 CI (12%) and 9 SD (53%). By EUNMET, there were 2 CR (12%), 4 major responses (24%), 4 moderate responses (24%), 1 minor response (6%), 2 no response (12%), and 3 patients (17%) were lost to follow up or were too early to evaluate for response. Conclusions: Peg INF2a used at doses consistent with published clinical trials is active and well-tolerated when administered in a clinical setting outside of the support of a clinical trial. Given the majority of patients had previously failed cytoreductive therapy these results substantiate prior reports of efficacy of Peg INF2a in MPNs. Upcoming randomized clinical trials through the Myeloproliferative Disorders Research Consortium will help further define the role of Peg INF2a as first line therapy in high-risk MPNs. Disclosures: Mesa: Incyte: Research Funding; Lilly: Research Funding; SBio: Research Funding; Astra Zeneca: Research Funding; NS Pharma: Research Funding; Celgene: Research Funding.

Description: Young patients (age 〈 60 years) with essential thrombocythemia (ET) and no history of thrombosis are considered at low risk of thrombosis and therefore managed on a conservative approach with antiplatelet therapy or even without any treatment. JAK2 V617F and CALR exon 9 mutations are the most frequent molecular alterations observed in ET, with CALR-positive ET being considered a distinct clinical entity due to its higher platelet counts and lower incidence of thrombosis as compared with JAK2 V617F-positive ET. There is some evidence supporting a role for antiplatelet therapy in JAK2 V7617F-positive neoplasms. However, the role of antiplatelet therapy in CALR-positive ET has not been studied. The aim of the present study was to assess the effect of antiplatelet therapy in the primary prevention of thrombosis in patients with CALR-positive ET without indication of cytoreductive therapy. For such purpose, 240 patients (107 males, 133 females) diagnosed with ET at a median age of 42 years (range 13-59) were included in a multicenter retrospective study. Initial treatment consisted of antiplatelet therapy (n=109) or careful observation (n=108), whereas 23 patients received cytoreduction since diagnosis and were excluded. During a median follow up of 8 years, 137 patients were started on cytoreductive therapy because of the following indications: age 〉 60 years (n=10), thrombosis (n=10), bleeding (n=2), microvascular symptoms (n=18), extreme thrombocytosis (n=89), and others (n=8). Median time free of cytoreductive therapy was 3.2 years. Thrombosis-free survival restricted to the time of cytoreductive therapy abstention was calculated using the Kaplan-Meier method. Variables attaining a significant level at the univariate analysis were included in a Cox proportional hazard model. During the period of abstention of cytoreductive therapy, a total of 10 thrombotic events and 8 major bleeding episodes were registered. The probability of thrombosis at 3 years was 5% in patients managed with careful observation and 1% in those receiving antiplatelet therapy (p = 0.2). At multivariate analysis, antiplatelet therapy did not result in a lower risk of thrombosis after correction for age, sex and presence of cardiovascular risk factors. Interaction studies did not identify any subgroup of patients that benefited from antiplatelet therapy in thrombosis prevention. Regarding major bleeding, patients receiving antiplatelet therapy experienced a higher rate than those managed on observation (3-year probability of major bleeding, 5.5% and 0%, respectively, p=0.05). At multivariate analysis, antiplatelet therapy was associated with a tendency towards and increased risk of major bleeding (HR: 7.7, 95%CI: 0.9-66.2, p=0.06) independently of platelet count at diagnosis, age and gender. In conclusion, CALR-mutated low-risk ET patients under cytoreductive therapy abstention may not obtain a clear benefit from antiplatelet therapy since the increase in the rate of bleeding may offset the reduction in the rate of thrombosis Disclosures García-Gutierrez: Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Ariad: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Harrison:CTI Biopharma: Consultancy, Honoraria, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau; Gilead: Honoraria; Sanofi: Honoraria, Speakers Bureau; Shire: Speakers Bureau. Cervantes:Sanofi-Aventis: Consultancy; Novartis: Consultancy, Speakers Bureau; CTI-Baxter: Consultancy, Speakers Bureau. Vannucchi:Shire: Speakers Bureau; Baxalta: Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Description: Abstract 5053 Background: The Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) is a concise instrument of patient reported outcomes (PRO) designed to assess the unique spectrum of symptoms present in the majority of patients (Mesa et. al. Cancer 2007). We sought to validate the Swedish Translation of the MPN-SAF which addresses 19 separate symptoms reported by MPN patients. Methods: We utilized the standard practice of PRO translation in which 3 independent translations are created by 3 independent translators fluent in both languages. A fourth translator then discussed the translations with the other translators and a consensus translation was obtained. Patients self completed the MPN-SAF: Swedish at the time of a physician office visit and the Swedish EORTC-QLQ-C30 was co-administered for validation purposes. Results: Patients and Symptomatic Burden: 114 patients were prospectively enrolled (ET (N=53; 47%), PV (N=53; 47%) and MF (N=8; 6%)) a median of 6 years (range:0-42) from their diagnosis. Patients were of a median age (68; range 27–88 years) and gender (53% females) typical of the disease. 78% (N=88) had received some form of non-aspirin medical therapy for their disease, and 75% were on therapy at the time of completing the questionnaire. Patients frequently had a history of either thrombotic events (26%) and/or hemorrhagic events (10%). The MPN-SAF measured 19 items in the enrolled patients (data summarized in Table 1). Validation Analysis: EORTC-QLQ-C30 Consistent with our experience with the MPN-SAF:English Pearson correlations between MPN-SAF-Swedish individual symptom scores and the Swedish EORTC-QLQ C30 showed excellent correlations with co-validation questions including fatigue, pain, headache, insomnia, early satiety, and sad mood (all p

Description: Background The Myeloproliferative neoplasms (MPNs) consists of the subtypes polycythemia vera (PV), essential thrombocythemia (ET), primary myelofibrosis (PMF), and MPN unclassifiable (MPN-U). The incidence rates of these diseases vary substantially between different reports, ranging from 1.15 to 4.99/100,000 person-years. However, in a recent metaanalysis, there was no significant difference in MPN incidence between Europe and North America and the variations in incidence may therefore reflect the quality of the cancer registers and reporting of MPNs. In addition, there is a limited number of reports on MPN incidence during more recent years. Therefore, we assessed the incidence of MPN based on the Swedish Cancer Register, a high-quality population-based cancer register between 2000 and 2012. Patients and Methods The Swedish Cancer Register was used to identify all patients diagnosed with an MPN between January 1st 2000 and December 31st 2012. These Swedish Cancer Registers have very high levels of quality and completeness. Between 2008 and 2012, the reporting of newly diagnosed MPN to the cancer register was 〉92%. Information on the Swedish population was obtained from the Human Mortality Database (www.mortality.org). Based on information from these registers, incidence rates of MPNs with 95% confidence intervals (CIs) were calculated. Confidence intervals were estimated on the log scale. In addition, the incidence rate in relation to MPN subtype, age group (18-39, 40-49, 50-59, 60-69, 70-79, and ³80 years), as well as calendar year of diagnosis was assessed. Results A total of 5,442 MPN patients were reported to the cancer register between 2000 and 2012. During these years, there were 1,810 incident cases of PV, 1,862 of ET, 636 of PMF, and 1,134 with MPN-U. Between January 1st 2000 and December 31st 2012, the population in Sweden increased from 8,861,426 to 9,555,893 inhabitants. The overall annual incidence rate of MPN was 5.83 (95% CI 5.68-5.99)/100,000 persons. The incidence rate of PV was 1.94 (1.85-2.03), ET 2.00 (1.91-2.09), PMF 0.68 (0.63-0.74), and MPN-U 1.22 (1.15-1.29) per 100,000 person-years. In addition, there was a strong correlation between age and incidence of MPN with incidence rates being substantially higher among the older age groups (Table). The overall incidence rate of MPNs increased during the study period, from 5.06 (4.55-5.62)/100,000 person-years in the year 2000 to 5.98 (5.45-6.55)/100,000 person-years in 2012. The incidence rate of PV was similar throughout the study period, the incidence was 2.05 (1.74-2.42)/100,000 person-years in 2000 and 2.12 (1.81-2.47)/100,000 person-years in 2012. The annual incidence rate of ET and PMF increased, from 1.62 (1.34-1.95) to 2.49 (2.15-2.87) per 100,000 persons for ET and from 0.36 (0.24-0.53) to 0.86 (0.67-1.10) per 100,000 persons for PMF between 2000 and 2012. Conversely, the incidence of MPN-U decreased, 1.03 (0.81-1.29) to 0.52 (0.38-0.71)/100,000 person-years between 2000 and 2012. Summary and Conclusions In this large population-based study, the incidence of MPN was higher than previously reported in both European and North American studies. As earlier lower incidence rates likely are an effect of limited coverage of cancer registers, there may be an underreporting of MPNs in many European and American countries. The increase in MPN incidence rates during the study period may reflect increasing life expectancy of the Swedish population, improved reporting to the cancer register as well as changes in the classification and diagnostic systems. Similarly, the decrease in incidence of MPN-U is also likely a result of improved diagnostics during more recent years. In conclusion, the MPN incidences rates reported here are presumably more accurate compared to earlier reports due to the high level of coverage and accuracy of the Swedish registers. Table 1. Incidence rates of MPNs overall and in relation to subtype and age at diagnosis Total number MPN diagnosed 2000-2012 Incidence/100 000 person-years (95% confidence interval) All MPN 5,442 5.83 (5.68-5.99) Subtype PV 1,810 1.94 (1.85-2.03) ET 1,862 2.00 (1.91-2.09) PMF 636 0.68 (0.63-0.74) MPN-U 1,134 1.22 (1.15-1.29) Age at diagnosis (years) 18-39 226 0.67 (0.59-0.76) 40-49 361 2.26 (2.04-2.51) 50-59 769 4.92 (4.58-5.28) 60-69 1,228 9.54 (9.02-10.1) 70-79 1,680 18.99 (18.1-19.9) 〉80 1,178 18.92 (17.87-20.03) Disclosures Landgren: BMJ Publishing: Honoraria; Bristol-Myers Squibb: Honoraria; Medscape: Honoraria; Onyx: Honoraria; Celgene: Honoraria; International Myeloma Foundation: Research Funding; Medscape: Consultancy; BMJ Publishing: Consultancy; Onyx: Research Funding; Bristol-Myers Squibb: Consultancy; Onyx: Consultancy; Celgene: Consultancy.

Description: Abstract 4095 Background: Symptomatic burden in myeloproliferative neoplasms (MPNs) is present in over 70% of MPN patients (Mesa et. al. Cancer 2007). We sought to validate a broadly applicable instrument (MPN-SAF) to assess symptoms in myelofibrosis (MF), essential thrombocythemia (ET) and polycythemia vera (PV). Methods: Using the previously validated MF-SAF as a base instrument, we added several key additional symptoms previously identified as present in all subtypes of MPNs including headaches, concentration, dizziness, extremity tingling, insomnia, sexual problems and mood changes on a 0 (absent) to 10 (worst-imaginable) scale. Validation: The MPN-SAF was administered jointly with the EORTC-QLQ-C30 as the co-validation instrument using prospective cohorts in the USA, Sweden and Italy. The translated MPN-SAF (Swedish and Italian) was created through a standard approach using teams of 4 translators working in concert. Results: Compiled MPN-SAF: Patient data: 402 MPN-SAF surveys were administered (English (25%), Italian (46%) and Swedish (28%)) in 161 ET patients (40%), 145 PV patients (36%), and 96 MF patients (24%), an average of 7.8 years (range 0 – 43 years) from their MPN diagnosis. Participants were of typical age (64.9, range 26 – 91 years) and gender (53% female) characteristic of disease. Prior hemorrhage (10%) and thrombosis (25%) were frequent. 68% of patients currently received cytoreductive therapy and 84% received cytoreductive therapy in the past. Patients and Symptomatic Burden: 19 items assessed in the MPN-SAF demonstrated consistently that the most common symptoms were fatigue (93%), decreased quality of life (84%), insomnia (65%), sad mood (65%), and sexuality problems (58%). The least common symptoms (

Description: Background Myelofibrosis (MF) is a clonal myeloproliferative neoplasm (MPN) associated with a high degree of symptomatology, progressive cytopenias and potential to transform into acute myelogenous leukemia (AML). Thrombocytopenia amongst MF patients is a proven negative prognostic indicator and predictor of transformation to AML. Ruxolitinib is an effective JAK inhibitor for MF symptoms and splenomegaly, but is not indicated in patients with severe thrombocytopenia. Phase III trials of pacritinib have shown alleviation of the MF symptom burden amongst patients with thrombocytopenia (ASCO 2015 Mesa et. al.). In this study, we assessed the symptom burden of MF patients with significant thrombocytopenia who were naïve to pacritinib. Methods Data was assessed from a prospectively collected international database of MF patients in which demographics, disease features, and MF symptoms utilizing the myeloproliferative neoplasm symptom assessment form (MPN-SAF; Scherber et al, 2011). The MPN-SAF includes the patient's perceptions of common MPN-related symptoms and overall quality of life (QOL) on a 0 (absent) to 10 (worst imaginable) scale. Total symptom score (TSS) was computed based on symptom items using the published scoring algorithm on a 0 (all reported symptoms absent) to 100 (all reported symptoms worst imaginable) scale. MF risk scores were calculated using the DIPSS criteria (Gangat, 2011). Thrombocytopenia was defined as a platelet count

Description: Abstract 1731 Background: Symptom burden in primary, post-ET and post-PV myelofibrosis (MF) is frequently severe and correlates with a poor prognosis. However, symptom manifestations are heterogeneous with variable presence of specific symptoms, splenomegaly and cytopenias. We sought to identify the spectrum and features of MF symptomatic phenotypes by cluster analysis of prospectively gathered information on MF symptoms and disease features. Methods: Data was collected among an international cohort of subjects with MF. Data included demographics, disease features and completion of the Brief Fatigue Inventory (BFI) and Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPN-SAF TSS) (Blood 2011; 118:401–408). Surveyed symptoms addressed key disease features on a 0 (absent) to 10 (worst-imaginable) scale. Cluster development was based on consideration of r-squared in hierarchical clustering using Ward's linkage. Final cluster assignment was based on the nonhierarchical k-means method. Comparisons between symptom clusters were based on ANOVA and chi-squared tests. Results: Subject Demographic and Disease Characteristics: Data from 329 prospectively enrolled persons with MF was collected (Chinese 102, French 54, German 19, Italian 22, Dutch 45, English 51, Spanish 29, Swedish 7) including 223 PMF, 67 post-ET MF and 39 post-PV MF patients. Participants were of typical age (mean 59) and gender (47% F). Among all participants, four natural symptom clusters were identified (Figure 1). Among clusters, disease features including leukopenia, thrombocytopenia, and enlarged spleen varied significantly between clusters (P

Description: Abstract 1726 Background: We previously reported that symptom burden among persons with ET and PV can be severe and adversely affect QOL. The presence of severe symptoms is linked to poor prognosis. There is considerable inter-subject heterogeneity regarding which symptoms are present in which subjects. No studies have empirically evaluated whether disease characteristics can be grouped in related symptom clusters. Using our previously validated 18 item Myeloproliferative Neoplasm Assessment Form (MPN-SAF) (Blood 2011;118:401–408) given in conjunction with the 9 item Brief Fatigue Inventory (BFI) (Cancer 1999;85:1186–1196), we sought to evaluate symptom burden by means of cluster analysis. Methods: Data was collected from an international cohort of subjects with MPNs including demographics, disease features and the completed BFI and MPN-SAF instruments. Surveyed symptoms included fatigue, early satiety, abdominal pain and discomfort, inactivity, headaches, concentration, dizziness, extremity tingling, insomnia, sexual difficulties, mood changes, cough, night sweats, pruritus, bone pain and fever on a 0 (absent) to 10 (worst-imaginable) scale. Development of symptom clusters was based on consideration of r-squared in hierarchical clustering using Ward linkage. Final cluster assignment was based on the nonhierarchical k-means method. Comparisons between symptom clusters were based on ANOVA and chi-squared tests. Results: Subject Demographic and Disease Characteristics: Data from 1,141 subjects with PV (N=519) and ET (N=622) was prospectively collected (Chinese 236, French 305, German 45, Italian 114, Dutch 191, English 56, Spanish 109, Swedish 85. Age (mean 59, range, 26–87) and gender (54% F) were typical. Five clusters were selected (Figure 1). Frequencies of prior bleeding, spleen size, anemia, presence of any lab abnormality, language, gender, and MPN type varied significantly between clusters (P

Description: Background The promising development of perspectives in innovative therapeutic interventions in myelofibrosis (MF) makes the establishment of large collaborative networks ready to assure reliable comparability of cases and increasingly relevant data. This will provide assurance regarding efficiency and consistency in the development of clinical and epidemiological knowledge. We report here the results of the pilot phase of ERNEST, whose acronym defines its purpose: European Registry for Myeloproliferative Neoplasms: towards a better understanding of Epidemiology, Survival and Treatment. This project promoted by the European LeukemiaNet (ELN) collaboration is coordinated by the Fondazione Mario Negri Sud (Italy) and supported by an unrestricted educational grant by Novartis. Patients and Methods In order to test the feasibility of a prospective epidemiological outcome-oriented registry across centers, expected to vary in the characteristics of their populations and care practices, a retrospective analysis was implemented based on a strictly pre-defined protocol. Patients with Primary Myelofibrosis (PMF), Post- Essential Thrombocythemia Myelofibrosis (PET-MF) and Post- Polycythemia Vera Myelofibrosis (PPV-MF) which were diagnosed in the participant centers between January 2001 and December 2012, with available follow-up information, were eligible for inclusion. Chi-square test and Mann-Whitney test were used to compare data at presentation by diagnosis for categorical and continuous variables respectively. Standard time-to-event methods were used for data analysis, including log-rank test, Kaplan-Meier survival graphs, and Cox proportional hazards models to calculate hazard ratios along with 95% confidence intervals (CI). Multivariable analysis was performed adjusting for unbalanced and relevant prognostic covariates. Results From February 2013 to May 2014, we received data of 1209 evaluable patients from 13 centers in 5 European countries (Italy, Germany, Spain, United Kingdom, Sweden): 61% were PMF, 20% PET-MF and 19% PPV-MF (median age: 66 years). 23%, 37% and 40% of diagnosis were performed between 2001-2004, 2005-2008 and 2009-2012 respectively. Variability was found for the presence of constitutional symptoms (from 43% in PET-MF to 49% in PPV-MF); an excess of splenomegaly emerged in PPV-MF cohort (84% vs 74% and 75% in PMF and PET-MF respectively). Mean value + SD of Hb, WBC and PLT were: 13.9 + 16.5 g/dl, 17.4 + 30.8 109/l, 372 + 316 109/l respectively with higher levels of Hb and WBC in PPV-MF patients than PET-MF and PMF (p