Huang, Jocelin

Abstract BACK GROUND Primary myelofibrosis (PMF) leads to weight loss, splenomegaly and constitutional symptoms (Cancer2007;109:68–76) and hypocholesterolemia associated with decreased survival (Blood2007;110:a2548). Initial trials of JAK2 inhibitors have demonstrated improvements in these (JCO2008;26:a7004), yet little objective data exists regarding the dynamic changes in weight and spleen size during the course of PMF. METHODS We analyzed the Mayo PMF database for patients with information on disease prognosis, presentation, therapies, height and weight at diagnosis, and outcomes. Additionally, when available, we analyzed additional weights during the clinical course, the body mass index (BMI- (weight/(height*height)), spleen size, and peripheral blood studies including lipids. Results: 370 patients with PMF were identified with 193 (52%) having a weight at the time of diagnosis, the remainder had a weight obtained a median of 10.0 months (range 1.8–159) after diagnosis. Additionally, 210 patients (57%) had a weight value available from 1–3 additional time points during the course of their disease. At PMF diagnosis patients had a median BMI of 25.3 (range 17.6 to 38.4), with 53% considered overweight (USA Norms (NHANES 2004): 66% and 32.2% are considered overweight or obese). Although weight lost prior to diagnosis unclear, only 2% of patients would be deemed “underweight” at diagnosis. Serial analysis demonstrated 67% experienced a decrease in weight over time, with 23% and 6% experiencing a >10% or 20% decrease, respectively. Overall during the course of illness 65% of patients remained in the same BMI category with 27% dropping to a lower category and 8% gaining in a category (Table 1). Table 1. Distribution of Body Mass Index and Spleen Size in 370 PMF patients followed serially DX of PMF Weight 2 Weight 3 Weight 4 Underweight BMI<18.5 2% 1% 2% 2% Normal BMI=18.5–24.9 45% 41% 41% 54% Overweight BMI=25–29.9 33% 42% 41% 35% Obese BMI>30 20% 16% 16% 10% Spleen Size (cm BLCM) (median: range) 5.0 (0–30) 6 (0–33) 7 (0–33) 7.5 (0–28) Time from PMF DX (median(range) months) 0 10.3 (1.8–159) 28.3 (6–191) 57 (15–258) Major weight increases were rare <1%, and might include buildup of fluid or splenic mass. Indeed spleen sizes generally increased during the course of the illness, with 51% having “massive” splenomegaly (either >10 (45%) or >20 (20%) cm below left costal margin or requiring splenectomy (19%)). Massive splenomegaly was not associated with weight loss or weight gain, suggesting increasing splenic mass came at the expense of alternate tissue mass (muscle and or fat). Median survival for the entire cohort was 77 months and PMF prognostic scores being valid (Lille PMF score p<0.01; IWG-MRT PMF Score - Submitted separately Cervantes et. al. p<0.01), however BMI number and category was not independently predictive of survival. Additionally, neither percentage of weight loss nor changing BMI category were associated with decreased survival. Although splenomegaly was not independently associated with decreased survival, the need for splenectomy clearly was (p=0.02). Consistent with our prior observation hypocholesterolemia (total <150 (median of 151 (range 12–366) or a HDL cholesterol of <60 (median 77 (range 25–248)) were associated with decreased survival (p<0.01 and =0.05, respectively). Decreasing weight in PMF patients was most highly correlated with decreases in HDL (p=0.03). Hypocholesterolemia was highly associated with splenomegaly (p<0.001 for spleen size >10 cm at any point during disease course). Conclusions: Weight loss is common in most PMF patients, despite the confounders of edema and increasing splenomegaly which could mask the degree of loss of lean body mass. Although few PMF patients are considered “underweight” by BMI standards, the distribution compared to USA norms suggest a lower weight distribution. Additionally, patients during the course of their illness are most likely to fall from a BMI overweight category to a “normal” category which may underestimate the true degree of catabolism of muscle mass occurring. Although not independently associated with decreased survival, weight loss remains common and a sign of advancing disease in this terminal illness. More precise methodology to estimate true lean muscle mass lost or gained may yield a better understanding of the hypercatabolic state seen in PMF. Efficacious therapy (such as potentially a JAK2 inhibitor) will likely reverse the trend of weight loss in these patients.

Abstract BACKGROUND: In myelodysplastic syndromes (MDS) without excess blasts, red blood cell (RBC) transfusion requirement has been associated with poorer overall (OS) and leukemia-free (LFS) survival, suggesting that transfusion dependency is a marker of more severe disease (JCO2005;23:7594). We recently reported similar results in refractory anemia with ring sideroblasts (RARS): RBC transfusion requirement was an IPSS-independent adverse prognostic factor, but neither serum ferritin nor transfusion burden had prognostic value (AJH2008;83:611). Here, we examine the prognostic relevance of serum ferritin, need for RBC transfusions at time of diagnosis, and total transfusion burden in primary myelofibrosis (PMF). METHODS: We reviewed medical records to ascertain the clinical and laboratory features of 185 consecutive patients diagnosed with PMF according to the 2001 World Health Organization (WHO) criteria. Patients were excluded if ferritin measurements at time of diagnosis were unavailable. OS and LFS curves were constructed by Kaplan-Meier method, taking the interval from the date of diagnosis to death, leukemic transformation, or last contact. Log-rank test was used to test the homogeneity of survival curves over different groups. Cox proportional hazards model was utilized to determine the impact of various clinical and laboratory variables on OS and LFS. RESULTS: Clinical characteristics at diagnosis: Median age was 58 years (range 15–81; 110 males). Median serum ferritin level at diagnosis was 164 ng/mL (range 1–3903) and was ≥1000 ng/mL in 22 patients (12%). 101 (55%), 65 (35%) and 19 (10%) patients were assigned low, intermediate- and high-risk disease category (Blood1996;88:1013). In addition, 32 (17%) patients required RBC transfusions, 33% had constitutional symptoms and 39% displayed ≥ 1% circulating blasts. Where evaluated, 40% of the patients had cytogenetic abnormalities and 56% JAK2V617F. Events during the disease course: At a median follow-up of 28 months (range 0.5–231), 79 (43%) deaths and 15 (8%) leukemic transformations were documented. During this period, 126 (68%) patients required some form of therapy other than transfusion, including splenectomy in 33 (18%); only 4 underwent allogeneic stem cell transplantation. Causes of death were documented in 33 instances and none were attributed to iron overload. Median peak serum ferritin level during the disease course was 231ng/mL (range 9–13,080); 144 (78%) patients had peak levels <1000 ng/mL, 28 (15%) between 1000 and 3000 ng/mL, and 13 (7%) above 3000 ng/mL. Number of total RBC transfusions ranged from none to 121. Iron chelation therapy was reported in 62 patients (34%). Prognostic factors for OS and LFS: Kaplan-Meier projected median survival was 72 months. By univariate analysis, increased serum ferritin level at diagnosis considered as either a continuous (p<0.0001) or categorical (≥ 1000 ng/mL) variable (p<0.0001), RBC transfusion requirement at diagnosis (p<0.0001) and higher number of total RBC units transfused during the course of the disease (p=0.004) were all associated with inferior survival. However, only RBC transfusion requirement at diagnosis sustained its prognostic significance when age and conventional prognostic risk scores were added to the multivariable model as covariates. Similarly, a peak serum ferritin level of > 3000 ng/mL documented during the disease course was not detrimental to survival. History of iron chelation therapy was associated with shortened survival (p=0.003). Multivariable analysis that included previously described risk factors for LFS also identified RBC transfusion requirement at diagnosis as an additional and independent risk factor. CONCLUSIONS: Serum ferritin level at time of diagnosis or during the disease course of PMF lacks independent prognostic value for either OS or LFS. The same is true for total transfusion burden. However, although hemoglobin <10 g/dL is a component of all currently utilized prognostic scoring systems for PMF, the presence of a more severe erythropoietic defect as indicated by RBC transfusion need at time of diagnosis has an additional adverse prognostic value for both OS and LFS.

Abstract BACKGROUND: The potential risks of tumor growth promotion and thromboembolism associated with erythropoietin (Epo) therapy warrant cautious use of erythropoiesis stimulating agents (ESA). Recent data suggest a surprising and significant association between ESA use and increased incidence of leukemic transformation in primary myelofibrosis (PMF) (data from an analysis separately submitted for American Society of Hematology meeting, 2007). It is prudent, therefore, to avoid unnecessary ESA exposure in PMF, especially in patients with low likelihood of treatment response. METHODS: Diagnosis of PMF was based on World Health Organization criteria. Study inclusion required availability of treatment history with ESA and adequate follow-up. We excluded patients who were receiving hemoglobin-improving agents concomitantly with an ESA, such as prednisone, androgens, danazol, or thalidomide. Transfusion dependency was defined by a history of minimum 2 units of red blood cell transfusions in a 1-month period for a hemoglobin < 8.5 g/dL, not associated with bleeding. An adequate treatment response was defined as a minimum 2.0 g/dL increase in hemoglobin level or becoming transfusion-independent over a minimum 1-month period. RESULTS: A master database of PMF patients seen at the Mayo Clinic from 1976 through 2006 was queried to identify 43 patients (median age 67 years; 35% females) treated with ESAs and in whom adequate follow-up was available to determine response. Prior to ESA treatment, median hemoglobin was 9.2 g/dL (range 7.0–11.9), and 16 (37%) were red blood cell transfusion-dependent. In 25 patients, pre-treatment serum Epo level was available (median 34 mU/mL; range 2–323). Among the 43 study patients, 16 (37%) were previously treated with other PMF-specific therapies, and 18 (42%) were receiving cytoreductive treatment concurrent with an ESA. Overall, 23% of patients (10 of 43) responded to treatment with ESA. The response rate was 0% (0 of 16) in the transfusion-dependent group compared to 37% (10 of 27) in the transfusion-independent group (p=0.007). Among the transfusion-independent patients, the proportion of ESA responders was significantly higher in the presence of a baseline hemoglobin level < 10 g/dL prior to treatment (p=0.009). ESA response was not correlated with baseline serum Epo level in the context of either all 43 study patients (p=0.68) or the 27 transfusion-independent patients (p=0.39). ESA response was not affected by PMF-specific treatment history (p=0.46), use of concurrent cytoreductive therapy (p=0.28), cytogenetic findings (p=0.62), JAK2V617F presence (p=0.69) or its allele burden at time of initial PMF diagnosis (p=0.16). CONCLUSIONS: Clear benefit of ESAs in PMF is limited to red blood cell transfusion-independent patients and those with baseline hemoglobin levels less than 10 g/dL.

Abstract BACKGROUND: We sought to determine the prognostic relevance of aberrant serum lipid values in the myeloproliferative disorders (MPDs) of primary myelofibrosis (PMF), polycythemia vera (PV), and essential thrombocythemia (ET). METHODS: The Mayo MPD patient institutional database was queried to identify clinical history and lipid profiles (within a year of diagnosis). Serum cholesterol (CHOL), low density lipoprotein (LDL-C), high density lipoprotein (HDL-C), and triglycerides (TRI) were assessed compared to clinical outcomes. RESULTS: 558 patients with MPDs (PMF 28%, PV 27%, and ET 45%) (median age at diagnosis of 56 (range18–81)) were identified. A lipid profile obtained a median of 0.0 months from diagnosis (range (-8 to 12 months) from MPD patients displayed low CHOL, LDL-C, and higher HDL-C than typical for the USA. Amongst MPD disease types PMF patients had lower CHOL (p<0.001) and HDL (p<0.001) compared to ET and PV (see table). Amongst PMF patients, although hypocholesterolemia was not a surrogate for malnutrition (p=0.13) median serum albumin 4.1 g/dL (range 2.7–4.8)), there was correlation with the presence of weight loss, hypercatabolic symptoms, and worse Mayo-CBC myelofibrosis prognostic scores (Cancer2006;106:623; p<0.01). Amongst the study group PMF patients had the poorest survival (followed by PV then ET; p<0.001). Decreased cholesterol (CHOL <150mg/dL, or HDL <60 mg/dL) was associated with decreased survival (P<0.001), but only in PMF patients (see figure). Decreased PMF survival was also associated with traditional PMF risk factors of hemoglobin <10g/dL, leukocytes <4 or >30 × 10(9)/L, platelets <100 × 10(9)/L, and circulating blasts. In multivariate analysis (Cox-Proportional Hazard) only the Mayo-CBC score, hemoglobin <10g/dL, circulating blasts and decreased CHOL remained significant for decreased survival (p<0.001). CONCLUSIONS: The presence of hypocholesterolemia is very common in patients with PMF and is independently associated with inferior survival. Survival by HDL-C and Serum Cholesterol (CHOL) in 154 patient’s with Primary Myelofibrosis Survival by HDL-C and Serum Cholesterol (CHOL) in 154 patient’s with Primary Myelofibrosis Lipid Distributions in 558 MPD patients VALUE/ NCEP CATEGORY PMF (N=154) PV (N=149) ET (N=255) NHANES (USA MEANS;95th CI) NCEP: National Cholesterol Education Program: NHANES (National Health and Nutrition Examination Survey (values for all races ages 65–74) Serum Cholesterol (Median) 149 mg/dL 179 mg/dL 199 mg/dL 221 mg/dL (153–301) −>200mg/dl (Desirable) 10% 31% 48% −150–200mg/dL (Desirable) 39% 25% 41% −100–149mg/dL (Desirable) 41% 41% 9% −<100mg/dL (Low) 10% 3% 2% LDL Cholesterol (Median) 33 mg/dL 41 mg/dL 49 mg/dL 149 mg/dL (87–217) −>100mg/dL (Low to high risk) 1% 1% 1% −<100mg/dL (Optimal) 99% 99% 99% HDL Cholesterol (Median) 79 mg/dL 118 mg/dL 108 mg/dL 45.7 mg/dL (29–71) −>60mg/dL (Optimal) 74% 90% 91% −40–60mg/dL (Normal) 16% 10% 8% −<40mg/dL (Low) 10% 0% 1% Triglycerides (Median) 151 mg/dL 89 mg/dL 116 mg/dL 145 mg/dL (62–285) −>200mg/dL (High) 28% 0% 3% −150–199mg/dL (Borderline) 23% 6% 14% −<150mg/dL (low) 49% 94%% 83%

Abstract Background : Two previous studies have reported significant but inconsistent associations between the presence of JAK2V617F in primary myelofibrosis (PMF) and older age at diagnosis, risk of thrombosis, higher leukocyte count, and inferior survival (Tefferi, et al. BJH2005;131:320, Campbell, et al. Blood2006;107:2098). The clinical relevance of V617F allele burden in PMF has not been previously studied. Methods : Diagnosis of PMF was based on the World Health Organization criteria and study eligibility included the availability of bone marrow-derived DNA that was collected either at time of diagnosis or within one year of diagnosis. Quantitative allele specific PCR was utilized to meaure V617F allele burden. Results I. V617F-positive vs. V617F-negative comparisons: A total of 199 patients (60% males; median age 61 years) were suitable for analysis of comparisons between mutation-positive and mutation-negative disease. The Dupriez prognostic scoring system (PSS) risk distributions were 61% low-risk, 31% intermediate-risk, and 8% high-risk. Hypercatabolic symptoms were present in 27% of the patients and ≥1% peripheral blood (PB) blasts in 37%. At a median follow-up of 23 months (range 0–266), 57 patients (29%) had died, 17 (9%) developed leukemic transformation (LT) and 10 (5%) experienced major thrombosis. V617F mutational frequency was 58%. Univariate analysis identified older age (p=0.0007), platelet count ≥ 100 x 109/L (p=0.05), and PB blast percentage < 3% (p=0.001) as being associated with a positive mutational status; all three variables sustained their significance during multivariable analysis. The presence of the mutation did not affect the incidence of thrombosis (p=0.78), overall survival (p=0.22) or leukemia-free survival (p=0.5). Results II. Clinical correlates of V617F allele burden: Quantitative measurement of V617F allele burden was performed in 129 patients that were divided into four groups: V617F-negative (n=53) and V617F-positive with mutant allele burden in the lower quartile (n=19), middle quartiles (n=38), or upper quartile (n=19) range (median and range of V617F allele burden ratio was 29% and 1% to 74%). Kaplan-Meier plots revealed significantly shortened overall (Figure; p = 0.0008) and leukemia-free (p = 0.01) survival for the lower quartile allele burden group; survival significance was sustained in a multivariable analysis that included the Dupriez PSS. Lower quartile allele burden was also associated with lower leukocyte count (p = 0.003) and presence of hypercatabolic symptoms (p=0.05). Thrombosis incidence was not affected by allele burden. Conclusions: In PMF, patients with a low V617F allele burden, compared to those with either undetectable (i.e. wild-type) or higher allele burden, display significantly shorter overall and leukemia-free survival. In contrast, the presence or absence of the mutation, by itself, does not result in distinct groups that differ significantly in terms of survival, LT, or incidence of thrombosis. These data suggest that a low V617F allele burden in PMF is a surrogate for the development of dominant V617F-negative subclones that are more likely to undergo LT. Figure Figure

Abstract BACKGROUND: Information regarding risk factors for leukemic transformation (LT) in primary myelofibrosis (PMF) is limited, although both leukocytosis and abnormal cytogenetics have previously been implicated. The current retrospective study examines clinical variables at diagnosis as well as specific treatment modalities for their effect on LT in PMF. METHODS: Diagnoses of PMF and LT were based on World Health Organization criteria. In addition, study inclusion required availability, for review, of bone marrow histology and clinical data obtained at or within 6 months of diagnosis but prior to treatment intervention. Statistical methods used were standard and included Cox regression analysis of leukemia-free survival (LFS). RESULTS: A master database of PMF patients seen at the Mayo Clinic from 1976 through 2006 was queried to identify 311 patients who fulfilled the aforementioned stipulated criteria for study inclusion; median age was 57 years and 41% were females. At presentation, 30% of the patients displayed a hemoglobin level (Hgb) of < 100 g/L, 20% a leukocyte count of < 4 or > 30 x 109/L, 18% a platelet count of < 100 x 109/L, 12% an absolute monocyte count (AMC) of ≥ 1 x 109/L, 28% hypercatabolic symptoms and 35% a peripheral blood (PB) blast percentage of ≥ 1; 27 patients (9%) had a PB blast percentage of ≥ 3. Dupriez prognostic scoring system distribution for high, intermediate, and low risk disease was 30 (10%), 94 (30%), and 187 (60%) patients. Among 182 and 139 evaluable patients, 74 (41%) and 80 (58%) displayed cytogenetic abnormalities and JAK2V617F, respectively. At a median follow-up of 27 months (range 0–282), 27 cases (9%) of LT were documented at a median time from diagnosis to LT of 26 months (range 0.8–266). Effect of clinical and laboratory variables at diagnosis on leukemic transformation By univariate analysis, LFS was negatively affected by anemia (p=0.04), leukocytosis (p=0.04), PB monocyte count ≥ 1 x 109/L (p=0.02), platelet count of < 100 x 109/L (p=0.004), hypercatabolic symptoms (p=0.03) and PB blast percentage of ≥ 3 (p<0.0001); LFS was not affected by PB blast percentage of > 1 but < 3 (p=0.49). By multivariable analysis, significance was sustained only for PB blast percentage of ≥ 3 (p = 0.0002) and platelet count of < 100 x 109/L (p = 0.02) with hazard ratios (HR) of 5.8 and 2.8 and 95% confidence intervals (CI) of 2.3–14.6 and 1.2–6.6, respectively. The presence of JAK2V617F did not affect LFS (p=0.98). Effect of specific treatment on leukemic transformation By univariate analysis, LT was significantly associated with history of splenectomy (p=0.01) and treatment with erythropoiesis stimulating agents (ESA; p=0.004), danazol (p=0.007), and androgens (p=0.03) but not with hydroxyurea (p=0.17), interferon alpha (p=0.95), thalidomide (p=0.26) or other drugs. On multivariable analysis, significance was sustained for both ESA (p = 0.005; HR 3.1, CI 1.4–6.8) and danazol (p = 0.01; HR 3.4, CI 1.3–8.5), even when the aforementioned prognostic indicators at diagnosis were added as covariates to the multivariable model. CONCLUSIONS: The current study identifies PB blast percentage of ≥ 3% and platelet count of < 100 x 109/L, at presentation, as independent risk factors for LT in PMF. Unexpectedly, the study also revealed an association between LT and treatment history with ESA or danazol. These observations are intriguing, considering recent reports on the possible harmful effects of ESA in certain solid tumors.

Abstract Background: Almost all cases of polycythemia vera (PV) and more than half of those with either essential thrombocythemia (ET) or primary myelofibrosis (PMF) harbor JAK2V617F. It has been previously shown that V617F-positive ET patients, as opposed to their mutation-negative counterparts, require lower doses of hydroxyurea (HU) for control of their platelet count. In the current study we looked for a similar scenario in PMF and PV. Methods: Study patients were identified by database inquiry based on the presence of treatment history with HU and adequate follow-up. Qualitative (PMF) and quantitative (PV) analysis of JAK2V617F was performed according to previously published allele specific PCR-based methods. Mutation analysis was performed on bone marrow samples collected at time of initial diagnosis or within one year of diagnosis. HU treatment response assignment was according to criteria set by the International Working Group for Myelofibrosis Research and Treatment. In PV, a complete response (CR) required normalization of blood counts associated with a more than 50% benefit in both phlebotomy requirement and splenomegaly. Partial response (PR) required either becoming phlebotomy independent or normalization of blood counts or a greater than 50% improvement in splenomegaly. Results: The study cohort consisted of 69 patients with PMF (median age 62 years; 36% females) and 56 patients with PV (median age 67 years; 45% females). In PMF, by univariate analysis, HU response was associated with a shorter disease duration (p=0.008), absence of previous therapy (p=0.01), older age at diagnosis (p=0.009), and presence of V617F (p=0.02). On multivariable analysis, only the latter retained its significance; HU response rate was 48% in V617F-positive patients (11/21 patients) and 8% in mutation-negative cases (1/12 patients). In PV, V617F allele burden correlated directly with HU response (p=0.05) and, in responding patients, inversely with HU dose (p=0.01; Figure). All 9 patients with upper quartile V617F allele burden responded (8 with CR) whereas 6 of the 11 (55%) HU non-responders displayed V617F allele burden in the lower quartile range. Among the 45 HU responders, the maximum daily dose of HU employed in all 9 patients in the upper quartile allele burden range and 4 of the 5 in the middle quartiles range was below 1500 mg. In contrast, 8 of the 31 patients (26%) in the lower allele burden quartile range required doses at 1.5 gm or more per day. Conclusion: The current study suggests that response to HU therapy in both PMF and PV is more robust in the presence of JAK2V617F; the particular information is useful in identifying PMF patients who are likely to benefit from HU therapy and in individualizing HU starting dose in PV patients. Figure Figure

Abstract Abstract 3918 Poster Board III-854 BACK GROUND We have previously demonstrated that the myeloproliferative neoplasms (MPNs) of primary myelofibrosis (PMF), polycythemia vera (PV), and essential thrombocythemia (ET) can lead to weight loss, splenomegaly and constitutional symptoms (Cancer 2007;109:68–76). Additionally we have demonstrated that hypocholesterolemia in MPN patients is associated with decreased survival (Blood 2007;110:a2548). Given that current JAK2 inhibitor trials are demonstrating the ability to reverse MPN associated splenomegaly (Haematologica 2009;94(Suppl 2)439 a1088) and cachexia (Blood 2008;112(11):a1760) we sought to determine the baseline natural history for these variables in patients treated prior to the JAK2 inhibitor era. METHODS We analyzed the Mayo MPN database for patients (not treated with JAK2 inhibitors) with information on disease prognosis, presentation, therapies, height and weight at diagnosis, and outcomes. Additionally, when available, we analyzed additional weights during the clinical course, the body mass index (BMI- (weight/(height*height)), spleen size, and peripheral blood studies including lipids. Results: Patients 783 patients with MPNs (followed for a median of 51 months (range 1-871 months); 60% having expired) were identified for the analysis (PV=158, ET=255, PMF=370) with 541 (69%) having a weight at the time of diagnosis, the remainder had a weight obtained a median of 7.8 months after diagnosis. Additionally, 508 patients (65%) had a weight value available from 1–3 additional time points during the course of their disease. Corresponding measurements of splenomegaly, or absence thereof, were noted in 766 cases (98%). Lipid panels (obtained within 18 months of diagnosis) were available in 264 patients. Results by MPN disease type are listed in the Table. Impact on prognosis Univariate analysis of variables discussed which negatively impacted survival included the subtype of MPN (not surprisingly worse for PMF p<0.001), weight loss of greater than 10% during the course of follow-up (P<0.001), or development of splenomegaly of >10 cm below the left costal margin (p=0.004) whereas hypocholesterolemia was significant only for the subset of PMF patients (P=0.03). The IWG-MRT International Prognostic Score (IPSS - Cervantes et. al. Blood 2009) was the only variable prognostically relevant in multivariate analysis (P<0.001). Conclusions Progressive splenomegaly, weight loss, and hypocholesterolemia are common across all MPNs but are most prognostically detrimental in PMF. Ongoing and future trials of JAK2 inhibitors will answer whether reversal of these latter hypercatabolic and proliferative manifestations of disease will improve outcomes for MPN patients. Disclosures: No relevant conflicts of interest to declare.