Mesa, Ruben A.

Abstract Abstract 2850 Myelofibrosis (MF), both primary myelofibrosis (PMF) and post essential thrombocytosis/polycythemia vera myelofibrosis (post ET/PV-MF), are chronic myeloproliferative neoplasms characterized by a progressive clinical course that leads to shortened survival. The heterogeneous nature of MF lends itself to a variable clinical course that commonly includes hepatosplenomegaly, constitutional symptoms, and progressive cytopenias. Medical therapy for myelofibrosis has been effective in palliation of common symptoms related to anemia, splenomegaly but allogeneic stem cell transplantation (ASCT) remains the only potentially curative therapeutic modality. The timing of ASCT, choice of conditioning regimen, patient selection and the impact of co-morbidities are critical to optimal use of this modality. We have retrospectively analyzed our experience for patients undergoing ASCT for primary and post ET/PV myelofibrosis at Mayo Clinic across all 3 sites: Scottsdale Arizona; Rochester, Minnesota; and Jacksonville, Florida. Methods: We conducted a retrospective review of all patients from 1992 to 2012 with PMF or post ET/PV-MF who underwent an ASCT at Mayo Clinic. This retrospective review included a waiver of informed consent and was approved by the Mayo Clinic Institutional Review Board. Patients that transformed to the MPN blast phase and individuals who underwent a second transplant for either relapse or graft failure were also included. Overall survival was estimated using Kaplan-Meier. Associations between prognostic factors and overall survival were assessed using Cox regression. Results: Baseline Patient Characteristics: Forty-eight patients (29 male) with a median age of 57 yrs (range 31–73) underwent ASCT. DIPSS-plus risk score was low in 2, intermediate 1 in 2, intermediate 2 in 9 and high in 35 patients. Disease type was PMF in 24, PV-MF in 10, ET-MF in 10, and MPN/MDS overlap in 4 pts. Eight patients evolved to the MPN-blast phase prior to transplant. JAK-2 mutation was positive in 27 patients and negative in 12 patients with JAK-2 status unknown in 9 patients. The median time from PV/ET to MF was 136 months (83–189 months) and from MF diagnosis to transplant was 59 months (3–144 months). All but 2 patients were red cell transfusion dependent prior to transplant (96%). Eight patients underwent splenectomy prior to transplant. Transplantation Characteristics: Patients who underwent ASCT received either myeloablative (MA, 13 pts) or reduced-intensity conditioning (RIC, 35 pts) regimen. The graft was from an unrelated donor in 22 pts and related donor in 26 pts with 44 being matched and 4 being mismatched. The myeloablative regimens included Bu/Cy, TBI/Cy, and Bu/Flu. The RIC regimens included flu/mel, Bu/Flu, FBM, and TBI/Flu. GVHD prophylaxis was with tacrolimus/MTX, CSA/MTX, and tacrolimus/MMF. Nineteen patients received ATG. Infectious disease prophylaxis, CMV monitoring, and additional supportive care measures were according to institutional guidelines. A majority of patients received peripheral blood stem cells with only 1 patient receiving bone marrow as the source of stem cells. Outcomes: The median time to neutrophil engraftment was 17.2 days. Two patients received a second transplant for relapsed disease. The incidence of graft failure was 10%. Graft versus host disease both acute and chronic occurred in 33 patients and 15 patients respectively. Day 100 overall survival was 92% and 2 year survival was 62% (95% CI 45–75%). There were no statistically significant associations between individual prognostic factors (DIPSS-plus classification, age, and HLA match) and survival. Conclusions: The Mayo Clinic national experience of ASCT for MF across our geographically diverse Cancer Center is encouraging. Our centers have transplanted 48 patients over the past 10 years with very favorable outcomes. Our results from a multi center practice are consistent with regards to survival, graft versus host disease, and types of transplants being performed compared to currently available published data from large single location transplant centers. This data helps confirm the prevailing knowledge that ASCT is a useful treatment. Disclosures: Mesa: Incyte: Research Funding; Lilly: Research Funding; Sanofi: Research Funding; NS Pharma: Research Funding; YM Bioscience: Research Funding.

Abstract Abstract 2834 Background: Myelofibrosis (MF), Polycythemia Vera (PV) and Essential Thrombocythemia (ET) are 3 classic BCR ABL negative myeloproliferative neoplasms. MF is comprised of both primary myelofibrosis (PMF) and those with an antecedent PV or ET (Post PV and Post ET MF, respectively). The term secondary MF (SMF) when used sometimes includes those with histologic myelofibrosis without an MPN (i.e. secondary to another myeloid neoplasm or autoimmune conditions) as well as MPN associated MF (PMF and Post PV/ET MF). Limited published epidemiology data is available on these disorders. Literature reports MF incidence in the range of 0.4–1.4 per 100000. The objective of this study was to estimate prevalence and incidence using 2 real world US health insurance claims databases. Method: The US IMPACT® (∼30M enrollees/year) and US MARKETSCAN (∼40M enrollees/year) were used to retrospectively identify unique patients with PMF, SMF, PV and ET between 1/1/08 and 12/31/10. These databases can track patients longitudinally over multiple years, are linked at the patient level by a unique identifier that is consistent across services, health plans, and time and shown to be representative of the US population. ICD9 CM codes were used to identify PMF, SMF, PV and ET. Any MF was defined as having a diagnosis of either PMF or SMF. Incident cohort was constructed by selecting patients who had their first MF (or PV or ET) in 2010 confirmed by absence of diagnosis 3 years prior. Prevalent cohort was constructed by identifying patients who had MF (or PV or ET) in a given year. From the MF cohort, post ET and post PV patients were identified as those who had any ET or PV diagnosis in the calendar year prior. Primary MF was defined as PMF diagnosis alone without prior PV or ET. Annual prevalence rates were calculated for each calendar year from 2008–10. Continuous enrollment was required during the time period being evaluated. Estimates were adjusted for age distribution from census data. Result: About 8.5M enrollees from IMPACT and 17M from MARKETSCAN each year were included in prevalence estimates. Mean age of MF patients was 61 years in IMPACT and 67 in MARKETSCAN. Age adjusted incidence estimates of MF were about 2.4 per 100000 per year using IMPACT database, 1.7 per 100000 per year from MARKETSCAN. There is a slight increase in MF prevalence over time: from 4.9 to 5.6 in IMPACT, 3.6 to 4.2 in MARKETSCAN. Among MF patients, about 35–40% had PMF, 10% were post-PV patients, 15% were post-ET patients and the remaining had MF arising from myelodysplastic syndrome (∼30%), lupus (∼2%) and other heme and solid tumors (∼3%). Mean age of PV patients was 55 and 36% were female in IMPACT database. In MARKETSCAN, mean age was 58 with 35% being female. Using IMPACT, annual age adjusted prevalence for PV was 57 cases per 100000. Estimates using MARKETSCAN varied from 45 to 48 cases per 100000. Age adjusted incidence of PV ranges from 22 to 27 cases per 100000 patients per year. Mean age of ET patients was 53 and 57 years in each database. In both, 67% of patients were female. Using US IMPACT, annual age adjusted prevalence for ET was 54 to 56 cases per 100000. Estimates using MARKETSCAN varied from 39 to 44 cases per 100000. Age adjusted incidence of ET ranges from 22 to 31 cases per 100000 patients per year. Conclusion: This is the first study utilizing two large national US claims databases to estimate prevalence of MPN disorders. In the US, MF prevalence ranges from 3.6–5.7 per 100,000 patients. Incidence estimates of MF range from 1.7–2.4 per 100,000 patients. PV prevalence estimates range from 45–57 cases and ET prevalence ranges from 39–57 cases per 100,000 patients. PV tends to affect more males while ET affects more female. These data provide compelling evidence to suggest that prevalence and burden of MPN associated MF is higher than has been reported in the past. Additional research using other national databases and/or study designs is needed to substantiate these findings. Disclosures: Mesa: Incyte: Research Funding; Lilly: Research Funding; Sanofi: Research Funding; NS Pharma: Research Funding; YM Bioscience: Research Funding. Mehta:Sanofi: Employment. Wang:Sanofi: Employment, Equity Ownership. Iqbal:Sanofi: Employment, Equity Ownership. Neumann:Sanofi-aventis: Employment. Zhang:Sanofi-aventis: Employment.

Abstract 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<0.05). Cluster 1: The “Fatigue Dominant with Few Lab Abnormalities” Profile (n=150 (46%; 69% PMF, 20% post-ET MF, 11% post-PV MF)). Cluster 1, the largest, is characterized by fatigue-dominant complaints in the setting of the lowest overall MPN-SAF TSS and highest proportion of males (59%). Individuals among this group have the lowest prevalence of laboratory abnormalities (65% total; anemia, 67%; thrombocytopenia, 20%) or clinical deficiencies including enlarged spleen (average 6.0 cm below costal margin), prior thrombosis (9%), prior hemorrhage (5%) or prior RBC-transfusions (20.4%). Interestingly, individuals in this group are most likely to have had prior splenectomy (5.8%). Cluster 2: The “Cognitive Complaints with Enlarged Spleen” Cluster (n=105 (32%; 65% PMF, 20% post-ET MF, 15% post-PV MF)). Cluster 2 is the 2nd largest cluster. Subjects have relatively few abnormal lab values (67% vs 65%–77%) but have high severity of fatigue, sexual difficulties, insomnia, inactivity and reduced QOL. These individuals have the largest spleen size (8.7cm below costal margin). Cluster 3: The “Nighttime and Cognitive Complaints” Group (n=53 (16%; 64% PMF, 25% post-ET MF, 11% post-PV MF)). Cluster 3 is the smallest cluster. Subjects have many cognitive and nighttime-related complaints including sexual difficulties, night sweats, insomnia, and concentration problems. Subjects with post-ET MF are predominant. This cluster also has the 2ndsmallest spleen size (7 cm) or history of prior thrombosis (9.6%), hemorrhage (7.8%) or requirement for transfusions (21.2%). Cluster 4: The “Severe Fatigue with Few End-organ Complaints” Cluster (n=21 (6%; 81% PMF, 14% post-ET MF, 5% post-PV MF)). Cluster 4 is the most symptomatic cohort with the highest proportion of subjects with PM. There is a lower frequency of end-organ complaints including abdominal pain, cough, and headaches. Symptoms including sexual difficulties, sad mood and insomnia are predominant. No subjects had prior splenectomy. Subjects also have the highest prevalence of prior thrombosis (29%), hemorrhage (14%), and transfusions (43%). Additionally, this cohort has the largest prevalence of lab abnormalities (77%) with thrombocytopenia (71%), leukopenia (41%) and anemia (41%). Conclusion: This analysis will allow us to examine a new framework for evaluating persons with MF using symptom profiles and is the 1st cluster evaluation of MF. Lab and physical findings contrast significantly between symptom clusters indicating these phenotypic symptoms likely result from etiological factors present in specific disease phenotypes. Future studies should evaluate whether there is a correlation between cluster profiles, prognosis and genotype. Disclosures: Kiladjian: Celgene: Research Funding; Novartis: Honoraria, Research Funding; Shire: Honoraria. Roy:Novartis, BMS: Speakers Bureau. Harrison:Novartis: Honoraria, Research Funding, Speakers Bureau; YM Bioscience: Consultancy, Honoraria; Sanofi Aventis: Honoraria; Shire: Honoraria, Research Funding. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees. Passamonti:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees. Mesa:Incyte: Research Funding; Lilly: Research Funding; Sanofi: Research Funding; NS Pharma: Research Funding; YM Bioscience: Research Funding.

Abstract Abstract 1739 BACKGROUND: Differences in symptom burden characteristics between persons of European and non-European descent with BCR-ABL negative MPNs including essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (MF) are not studied. We reported significant clinical and laboratory differences between these populations age at diagnosis and survivals (Blood 2011;119: 2469–73) which could affect symptom burden. Given China represents one-fifth of the global population, we aimed to evaluate MPN symptom burden among a cohort of Chinese MPN patients. METHODS: Data were collected from Chinese with MPNs and their physicians and compared these to a previously collected data from a cohort of subjects of predominately European descent (N=1488). Subject data included MPN-SAF (Blood 2011;118:401-8) and BFI score (Cancer 1999;85: 1186–96), demographics, and disease-related features. Statistical methods included ANOVA, chi-squared tests, and multiple regressions. RESULTS: Demographic and Disease Characteristics: 397 Chinese subjects were prospectively enrolled with a distribution of 172 (43%) ET, 102 (26%) PV, and 123 (31%) MF (of which 103 [84%] were PMF, 14 [11%] were post-ET MF, and 6 [5%] were post-PV MF). Median age (56.0 y) was younger in Chinese than in the European-descent cohort (63.0 y, p<0.001) despite relative gender equality. Laboratory abnormalities including anemia (76%, p<0.001) and disease features including bleeding (1%, p<0.001), were more common and present at a significantly higher incidences in the European-descent cohort than amongst Chinese. Chinese Symptom Severity and Incidence by MPN type: When comparing across MPN types, symptoms of worst fatigue, early satiety, abdominal discomfort, inactivity, concentration, depression, cough, night sweats, weight loss, and total MPN-SAF TSS score varied significantly (p<0.05) with MF being most severe for each symptom. Chinese versus European-descent Symptom Severity: After adjusting for age and MPN type, Chinese subjects had significantly higher mean severity for fever, sexual difficulties, and quality of life (Table 1). Symptoms of worst fatigue, early satiety, abdominal discomfort and overall BFI score had a significantly higher mean severity in the European descent cohort. Chinese versus European-descent Symptom Incidence: The European-descent cohort had significantly greater incidence of worst fatigue (90% vs 81%, p<0.001), abdominal pain (47% vs 35%, p<0.001), early satiety (65% vs 57%, p=0.005), concentration problems (64% vs 58%, p=0.04), numbness (63% vs 56%, p=0.02), insomnia (68% vs 58%, p<0.001), and depression (62% vs 56%, p=0.02) compared to Chinese subjects. In contrast, symptoms of dizziness (63% vs 57%, p=0.04), sexual difficulties (72% vs 61%, p<0.001), and fever (23% vs. 18%, p=0.03) were significantly worse amongst Chinese. CONCLUSION: We found a significant divergence in severity and incidence of key symptom burdens including QOL, fever, sexuality, dizziness, abdominal pain, early satiety, and fatigue between Chinese and persons of European descent with MPNs. Biological and cultural factors likely account for these differences and should be considered when interpreting outcomes of clinical trials of diverse populations. When the target of therapy is reversing symptoms, the best strategy may require revision for different populations. Disclosures: Mesa: Incyte: Research Funding; Lilly: Research Funding; Sanofi: Research Funding; NS Pharma: Research Funding; YM Bioscience: Research Funding.

Abstract Abstract 1432 Previously we demonstrated that inhibition of anti-apoptotic BCL-2 family members sensitize leukemic cells to 5-Azacytidine (5-Aza), using siRNA and pharmacological inhibition with the BH3-mimetic ABT-737, both in vitro and ex vivo (Bogenberger, JM., et. al. ASH Annual Abstracts 2011;118:Abstract 3513). Crucially, several anti-apoptotic BCL-2 members (e.g. BCL-2 and BCL-XL) required concurrent inhibition for potent and universal sensitization to 5-Aza. Anti-apoptotic BCL-2 proteins block the execution of programmed cell death (apoptosis) by binding to and counteracting two types of pro-apoptotic BCL-2 family proteins: the “BH3-only” proteins, including both activators (BIM and BID) and sensitizers (e.g. NOXA, PUMA, HRK), and the multi-domain effector proteins (BAX and BAK). Cells dependent on anti-apoptotic BCL-2 family members for survival have been defined as “primed for death” (Certo, M., et. al. Cancer Cell 2006 May;9(5):351-65). Importantly, the priming status reflects a dependence on anti-apoptotic BCL-2 family proteins and can be characterized with the BH3 profiling functional assay. This assay measures induction of mitochondrial outer membrane permeabilization (MOMP) in response to treatment with peptides derived from BH3-only proteins (Ni Chonghaile, T., et. al. Science 2011 Nov 25;334(6059);1129-33). Thus, the unique BH3 profile associated with a specific malignant cell population, is a function of the anti-apoptotic BCL-2 family member/s contextual expression in that cell population. Based on our observations of potent 5-Aza sensitization in combination with anti-apoptotic BCL-2 protein family inhibition, we hypothesized that BH3-profiling would predict response to 5-Aza. To address the potential utility of BH3 profiling in predicting response to 5-Aza in myeloid malignancies, we assayed a broad panel of AML-derived cell lines (N=13) by BH3 profiling and correlated BH3 metrics with 5-Aza response. Identical cell line passages were assayed by BH3 profiling and in 5-Aza drug dose response assays. The cell panel comprised lines derived from AML FAB subtypes M7, M6, M5, M4, M2 and M0, as well as diverse cytogenetics such as t(11;21), t(9;11), t(4;11), t(6;11), del 5q, del 7, and a broad spectrum of mutations such as FLT3, N-RAS, CDKN2A, NPM1 and DNMT3A. The panel included a normal karyotype AML cell line (CG-SH) (Munker, R., et. al. Leuk Res 2009 Oct:33(10):1405-8) and a blastic cell line derived from a patient with MDS (MDS-L) (Tohyama, K., et. al. Br J Haematol 1994 Jun;87(2):235-42). Partition modeling using several BH3 metrics discriminates 5-Aza response with statistical significance (N=13, Mann-Whitney p<0.01) between more sensitive (EC50<2uM) and less sensitive (EC50>2uM) AML lines. For instance, the Puma BH3 peptide alone distinguishes more sensitive from less sensitive cell lines (N=13, Mann-Whitney p=0.0046). Several more complex parameters, such as “Puma+Hrk”, “Puma+Noxa,” and “Bim+Puma+Noxa+Hrk,” also significantly discriminate 5-Aza response (Mann-Whitney p=0.0011). Using continuous variable analysis, a Puma+Hrk metric exhibited the strongest correlation with 5-Aza response (R2=0.85, p<0.0001), while an individual Puma metric yielded the second strongest correlation (R2=0.70, p=0.0004). In conclusion, BH3 profiling discriminates 5-Aza response and confirms a central role for anti-apoptotic BCL-2 members in 5-Aza response. Furthermore, HRK priming indicates that BCL-XL is an important, although not the sole, anti-apoptotic component determining 5-Aza response in myeloid cells. These BH3 profiling results are in agreement with our functional 5-Aza RNAi and BCL-XL/BCL-2 inhibitor data in combination with 5-Aza. Based on these results, we are currently evaluating BH3 profiles from 5-Aza responding and non-responding AML and MDS patients to validate BH3 profiling-derived metrics in predicting clinical outcomes to 5-Aza. Disclosures: Pierceall: Eutropics Pharmaceuticals: Employment, Equity Ownership. Lena:Eutropics Pharmaceuticals: Employment. Mesa:Sanofi: Research Funding; Incyte: Research Funding; Lilly: Research Funding; NS Pharma: Research Funding; YM Bioscience: Research Funding. Cardone:Eutropics Pharmaceuticals: Employment, Equity Ownership.

Abstract PRM-151 (PRM) is a recombinant form of Pentraxin-2, an endogenous human protein that acts at sites of tissue damage, inducing macrophage differentiation to prevent and reverse fibrosis. PRM has broad anti-fibrotic activity in multiple preclinical models of established fibrotic diseases and no dose limiting toxicities in phase 1 trials. Myelofibrosis (MF: primary (PMF), post-essential thrombocythemia (post-ET MF), and post polycythemia vera (Post PV MF)) is a myeloid malignancy characterized by progressive bone marrow (BM) fibrosis with resultant anemia, abnormal platelet and leukocyte counts, extramedullary hematopoiesis, and a well-defined symptom complex. This study investigated the potential of PRM in MF to reduce BM fibrosis and to improve key disease features including abnormal blood counts, symptoms, and splenomegaly. MF patients (pts) with Dynamic International Prognostic Scoring System (DIPSS) intermediate-1, intermediate-2, or high-risk disease and grade ≥ 2 BM fibrosis, either on no current therapy or on a stable dose of ruxolitinib (RUX) for ≥ 12 weeks and no improvement in spleen for ≥ 4 weeks, were eligible for stage 1 of this open-label adaptive trial. Assignment to one of the 4 treatment arms was per investigator and pt choice: PRM 10 mg/kg IV 1-hour infusion days 1, 3, 5, then weekly (QW) or every 4 weeks (Q4W), alone or with RUX, for 24 weeks. Primary endpoint was overall response rate by IWG-MRT (symptoms by MPN-SAF Total Symptom Score (TSS), spleen by palpation) and/or decrease in BM fibrosis by ≥ 1 grade with otherwise stable disease. BM biopsies were obtained at baseline, 3 and 6 months, and were evaluated centrally by two blinded hematopathologists. Pts with clinical benefit were allowed to continue treatment in an extension. At least one response in any arm was required for that regimen to be evaluated in Stage 2. Twenty seven pts were enrolled: 8 PRM QW, 7 PRM Q4W, 6 PRM QW + RUX, 6 PRM Q4W + RUX. Median age 67 years (52-85); 70% DIPSS Int-2 or High Risk; 52% PMF, 15% post-ET MF, 33% post-PV MF; 63% grade 3 BM fibrosis, Hemoglobin (Hgb) < 100 g/L in 56% and < 85 g/L in 26%, platelet count (PLT)< 100 x 109/L in 52% and < 25 x 109/L in 30%; 22% were JAK inhibitor-naive and 52% had received a prior JAK inhibitor (not including ongoing RUX). Twenty pts completed 24 weeks of therapy; 18 continued extension treatment. PRM-151 was well-tolerated alone and with RUX; most adverse events (AEs) were Grade 1/2 and unrelated, with 3 Grade 3 possibly related AEs and 5 possibly related serious AEs. Nine of 26 evaluable pts responded, for an overall response rate (ORR) of 35%, with 4 IWG symptom clinical improvements (CI) and 6 BM fibrosis responses (Table 1), with ≥ 1 response in each arm. One pt had a CI and BM response. Reduction in BM fibrosis was associated with normal erythroid microarchitecture, normal or decreased myeloid:erythroid ratio, and fewer paratrabecular megakaryocytes, all potential surrogates of improved bone marrow microenvironment. IWG stable disease was observed in 77% of pts, with trends of clinical benefit in Hgb, PLT, peripheral blood blasts, spleen, and symptoms (Table 2). In 14 patients (54%), all parameters were stable or improved. Conclusion: PRM-151 was well-tolerated in patients with advanced MF, with no evidence of drug-related myelosuppression and encouraging trends in both clinical and histologic aspects of the disease. Reduction in BM fibrosis, stable to improved hematologic parameters, symptom responses, and stable to reduced spleen size support further development of PRM-151 in MF. Table 1 Two additional subjects had decrease in bone marrow fibrosis but progressive disease. Number of Patients BM Fibrosis Grade at Last Study Timepoint 3 2 1 BM Fibrosis Grade at Baseline 3 8 3 1 2 1 4 2 Abstract 713. Table 2 Outcome Parameter Denominator (n) Clinical Benefit Pts with Improvement (n/%) ORR (primary endpoint) All evaluable pts (26) IWG-MRT CI AND/OR reduction in BM fibrosis by ≥ 1 grade 9 (35%) Hgb Hgb < 100 g/L (15) ≥10 g/L increase from baseline AND no transfusions or 50% reduction in transfusions if transfusion dependent 6 (40%) PLT PLT < 100 x 109/L (13) > 100 x 109/L AND increase of ≥20 x 109/L ; increase of ≥20 x 109/L if baseline < 50, AND/OR increase of ≥ 10 x 109/L with discontinuation of transfusions 8 (62%) Blasts ≥ 1% peripheral blasts (14) No peripheral blasts 3 (21%) Symptoms All evaluable pts (26) ≥ 25% reduction in TSS ≥ 12 weeks 10 (38%) Spleen Palpable spleen (19) ≥ 25% decrease ≥ 4 weeks AND any decrease ≥ 12 weeks 5 (26%) Disclosures Verstovsek: Incyte: Research Funding; Astrazeneca: Research Funding; Lilly Oncology: Research Funding; Roche: Research Funding; Geron: Research Funding; NS Pharma: Research Funding; Bristol Myers Squibb: Research Funding; Novartis: Research Funding; Celgene: Research Funding; Gilead: Research Funding; Seattle Genetics: Research Funding; Promedior: Research Funding; Cell Therapeutics: Research Funding. Mesa:Incyte, CTI, NS pharma, Gilead, Celgene: Research Funding; Promedior: Research Funding. Foltz:Janssen: Consultancy; Promedior: Research Funding; Gilead: Research Funding; Incyte: Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Gupta:Incyte Corporation: Consultancy, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Promedior: Research Funding. Mascarenhas:Novartis Pharmaceuticals Corporation: Research Funding; Incyte Corporation: Consultancy, Research Funding; Promedior: Research Funding. Ritchie:Celgene, Incyte: Speakers Bureau; Promedior: Research Funding. Hoffman:Geron: Consultancy, Membership on an entity's Board of Directors or advisory committees; All Cells LLC: Consultancy, Membership on an entity's Board of Directors or advisory committees; Promedior: Research Funding. Pozdnyakova:Sanofi: Consultancy; Incyte: Consultancy; Promedior: Consultancy. Hasserjian:Sanofi: Consultancy; Incyte: Consultancy; Promedior: Consultancy. Trehu:Promedior: Employment, Equity Ownership. Kantarjian:ARIAD, Pfizer, Amgen: Research Funding. Gotlib:Novartis: Research Funding, Travel Reimbursement, Travel Reimbursement Other; Sanofi: Research Funding; Gilead: Research Funding; Incyte: Consultancy, Honoraria, Research Funding, Travel Reimbursement Other; Promedior: Research Funding.

Abstract Abstract 1733 Background: Patients with myelofibrosis (MF) suffer from cytopenias, debilitating symptoms, and splenomegaly, all of which may contribute to shortened life expectancy. Cachexia is a common manifestation of MF. Its causes are multifactorial and include elevated inflammatory cytokines and mechanical effects of splenomegaly. It is a predictor of poor survival in patients with MF. Cachexia manifests as weight loss with low body-mass index (BMI; <20–21 kg/m2) (Strasser F. Sixth Research Congress of the European Association of Palliative Care; Wagner PD. Eur Respir J. 2008;31:492–501) and with metabolic indicators of poor nutritional status including hypocholesterolemia (total cholesterol <150 mg/dL or <3.89 mmol/L), which has been linked to poor prognosis in MF (Mesa et al. Blood 2007;110:abstract 2548). In the phase III, placebo-controlled, COMFORT-I study, ruxolitinib treatment significantly reduced spleen volume, improved MF-related symptoms, and exhibited a survival advantage compared with placebo in patients with MF. In this post hoc analysis, we investigated the effects of ruxolitinib treatment on weight and total cholesterol and the association of these changes with survival in COMFORT-I. Methods: Eligible patients in COMFORT-I were randomized to receive placebo (n=154) or ruxolitinib (n=155) at starting doses of 15 and 20 mg PO BID depending on baseline platelet count. Body weight was measured at baseline, and weeks 4, 8, 12, 16, and 24 and then every 12 weeks thereafter. Total serum cholesterol was measured at baseline and weeks 4, 12, 24, and then every 24 weeks thereafter. All patients receiving PBO completed crossover or discontinued within 3 months of the primary data analysis (when all patients completed 24 weeks and when half the patients remaining on study completed 36 weeks of treatment); thus, data for these patients were available for up to week 36 for weight and week 24 for total cholesterol. Kaplan-Meier analyses of overall survival were conducted in patients randomized to ruxolitinib stratified into 2 groups based on the median values separately for maximum weight gain and for maximum increase in total cholesterol during randomized treatment. Results: At baseline, mean body weight was similar between the treatment groups (72 kg, both) and mean total cholesterol was low (<150 mg/dL) in both treatment groups (ruxolitinib: 118 mg/dL; placebo: 115 mg/dL). The proportion of patients with BMI <22 were similar between the treatment groups (ruxolitinib: 23%; placebo: 28%) as was the proportion with total cholesterol <150 mg/dL (82%, both). Patients randomized to ruxolitinib experienced a gradual increase in body weight that stabilized by week 36 of treatment whereas patients receiving placebo experienced decreases in body weight over time (Figure 1). Similarly, total cholesterol increased in patients randomized to ruxolitinib and decreased in patients receiving placebo (Figure 2). Although total cholesterol increased over time in ruxolitinib-treated patients, increases did not exceed the upper limit of normal (199 mg/dL or 5.15 mmol/L). Nearly all patients randomized to ruxolitinib experienced weight gain (96% of patients) or an increase in total cholesterol (97% of patients). In patients randomized to ruxolitinib, weight gain above the median was associated with prolonged survival relative to lesser degrees of weight gain (HR=0.40; 95% CI: 0.18, 0.90; P=0.022; Figure 3). Similarly, increase in total cholesterol above the median was also associated with prolonged survival relative to a lesser degree of total cholesterol increase (HR=0.46; 95% CI: 0.21, 1.01; P=0.048; Figure 4). Meaningful comparisons with the placebo group based on the same stratification criteria could not be conducted as the majority of such patients experienced weight loss and decreases in total cholesterol while on the study; however, overall survival favored both ruxolitinib groups relative to all patients randomized to placebo even for ruxolitinib-treated patients with lower than median levels of weight gain or increase in total cholesterol. Conclusions: Ruxolitinib therapy promotes weight gain and improves total cholesterol in MF patients. These results suggest that the survival advantage exhibited by ruxolitinib over placebo in MF patients may be partly explained by reversal of the catabolic state and cachexia. Disclosures: Mesa: Incyte: Research Funding; Lilly: Research Funding; Sanofi: Research Funding; NS Pharma: Research Funding; YM Bioscience: Research Funding. Verstovsek:Incyte Corporation: Research Funding. Gupta:Incyte: 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; Celgene: Research Funding; YM Biosciences: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi#x2610;#x0025; Aventis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Mascarenhas:Incyte Corporation: Consultancy; Novartis: Clinical Trial Support, Clinical Trial Support Other. Atallah:Incyte: Consultancy, Research Funding. Sun:Incyte Corporation: Employment, Equity Ownership. Sandor:Incyte Corporation: Employment, Equity Ownership. Gotlib:Incyte Corporation: Consultancy, Honoraria, Support for travel to meeting for the study or other purposes from Incyte Other.

Abstract Background : Polycythemia vera (PV) is a myeloproliferative neoplasm driven by JAK/STAT activation and is associated with erythrocytosis and a broad symptom burden that may negatively impact patient quality of life (QoL). Hydroxyurea (HU) is often used as first-line therapy for high-risk patients but may not effectively control or reduce symptom burden. RESPONSE is a phase III trial comparing ruxolitinib (RUX) with best available therapy (BAT) in patients with PV who were intolerant of or resistant to HU according to modified European LeukemiaNet (ELN) criteria. The primary study endpoint (a composite of hematocrit control and ≥35% spleen volume reduction at Week 32) was achieved by 21% of patients in the RUX arm vs 1% in the BAT arm (P<0.0001); 77% of patients in the RUX arm achieved at least one component of the primary endpoint. The current analysis was conducted to evaluate the effect of RUX on PV-related symptoms and QoL measures in the RESPONSE trial. Methods : Patients with PV aged ≥18 years, resistant to or intolerant of HU (modified ELN criteria) with splenomegaly, and who required phlebotomy for hematocrit control were randomized 1:1 to receive open-label RUX 10 mg twice daily (BID) or BAT (administered based on investigator judgment). Dose adjustments were permitted (RUX, 5-mg BID increments [25 mg BID max]; BAT was adjusted per investigator judgment). Objectives of this analysis included assessment of improvement in symptom burden as assessed by patient-reported outcomes using the 14-item modified Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF), the Pruritus Symptom Impact Scale (PSIS), the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30), and the Patient Global Impression of Change. The 14-item MPN-SAF (graded from 0 [absent] to 10 [worst imaginable]) comprised symptoms related to cytokines (tiredness, itching, muscle ache, night sweats, and sweats while awake), hyperviscosity (vision problems, dizziness, concentration problems, headache, numbness/tingling, ringing in ears, and skin redness), and splenomegaly (abdominal discomfort and early satiety). Changes in total symptom score (TSS; maximum score = 140) and individual symptom scores from baseline to Week 32 were summarized by treatment group. For the EORTC QLQ-C30 Global Health Status/QOL score, the percentage of patients with a minimally important difference (MID) from baseline (10-point change) at Week 32 was summarized. Results : Overall, 222 patients were randomized (RUX, 110; BAT, 112). Median age (range) was similar between arms (RUX, 62.0 [34.0–90.0]; BAT, 60.0 [33.0–84.0]); the RUX and BAT arms were 60% and 71% male, respectively. At Week 32, a higher proportion of patients in the RUX vs the BAT arms had a ≥50% improvement in MPN-SAF TSS (49% vs 5%, respectively) and MPN-SAF symptom cluster scores (cytokine, 64% vs 11%; hyperviscosity, 37% vs 13%; splenomegaly, 62% vs 17%). Median percentage changes in individual symptom scores are presented in the Table. Mean changes from baseline at Week 32 on the 5 items of the PSIS indicated that the severity of pruritus and its interference on daily life improved with RUX (range, −1.5 to −2.2) and was unchanged/worsened with BAT (range, −0.1 to 0.3). Treatment with RUX vs BAT was associated with improved mean changes from baseline at Week 32 on EORTC QLQ-C30 symptom subscales, functional subscales, and Global Health Status/QOL (Table); 46% of RUX patients versus 10% of BAT patients achieved an MID in Global Health Status/QOL (Figure). At Week 32, RUX patients were more likely to rate their global impression of symptom changes as “very much improved” or “much improved” (67%) vs BAT patients (13%). Conclusion : In patients with PV who were resistant to or intolerant of HU, treatment with RUX was associated with greater and clinically meaningful improvements in PV-related symptom burden and QoL measures compared with BAT. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures Mesa: Incyte Corporation: Research Funding; CTI: Research Funding; Gilead: Research Funding; Genentech: Research Funding; Eli Lilly: Research Funding; Promedior: Research Funding; NS Pharma: Research Funding; Sanofi: Research Funding; Celgene: Research Funding. Off Label Use: Ruxolitinib is a JAK1/JAK2 inhibitor approved for the treatment of patients with intermediate or high-risk myelofibrosis, including primary myelofibrosis, post polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis. Verstovsek:Incyte Corporation: Research Funding. Kiladjian:Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Masszi:Novartis Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Durrant:Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Harrison:Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. He:Incyte Corporation: Employment, Equity Ownership. Jones:Incyte Corporation: Employment, Equity Ownership. Parasuraman:Incyte Corporation: Employment, Equity Ownership. Li:Novartis Pharmaceuticals: Employment, Equity Ownership. Côté:Novartis Pharmaceuticals: Employment, Equity Ownership. Habr:Novartis Pharmaceuticals: Employment, Equity Ownership. Vannucchi:Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract Abstract 1732 Background: In addition to chronic myelogenous leukemia (CML), the classic myeloproliferative neoplasms (MPNs) include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). The JAK2 V617F mutation (V617F) can be detected through genomic analysis of peripheral blood in 95% of PV and 50–60% of ET and MF patients (pts). These MPNs are often associated with debilitating symptoms and decreased quality of life (QOL). Systemic mastocytosis (SM) is an uncommon MPN in which proliferation of mast cells can result in mediator symptoms, as well as organ damage in advanced disease. We sought to compare the symptom burden of individuals with CML and SM to pts with classic MPNs in a more quantitative manner using a web-based recruitment design. Methods: Individuals with MPN were recruited through a web-based outreach effort. Participants gave IRB-approved consent, and completed on-line surveys of demographic information and questions based on the validated MPN-symptom assessment form (MPN-SAF). In addition, pts submitted saliva samples which were genotyped with SNP arrays based on the Illumina OmniExpress BeadChip, including probes for V617F. Regression analysis was used to evaluate the correlation between symptom responses and genotype data for 495 pts (118 PV, 121 ET, 97 MF, 85 SM, and 74 CML). For each MPN diagnosis, mean scores were calculated based on six fatigue-focused questions (Fatigue-6) and for six other symptoms (Symptom-6): early satiety, abdominal pain/discomfort, inactivity, night sweats, pruritis, and bone pain (ranked from 0–10; 10 = worst). ET pts' scores were used as the reference in the regression analysis based on prior data showing that ET pts have the lowest symptom burden among the classic MPNs. Individual symptoms, Fatigue-6, Symptom-6, and QOL (ranked 0–10; 10=worst) were analyzed using regression analysis against age, gender, diagnosis and V617F status. Results: Median age was 56 years (7–87), with 70% women. V617F was detected in 63% of classic MPN pts (87% PV, 46% ET, 56% MF). Analysis of Fatigue-6 scores revealed that age in years was negatively correlated with reported fatigue (β=-0.007 per year, P=0.032), while female gender and SM diagnosis were positively correlated with fatigue (female: β=0.33, P=2.4×10−4; SM: β=0.46, P=7.6×10−4). This trend was also seen for the Symptom-6: age (β=-0.025, P=5.8×10−4), female gender (β=0.73, P=1.4×10−4), and SM (β=1.8, P=5.0×10−10). Both Fatigue-6 and Symptom-6 were positively correlated with QOL, but Fatigue-6 had a much stronger association with QOL than did Symptom-6 (β=1.3, P=1.5×10−28 vs. β=0.36, P=1.2×10−11). When analyzed individually, abdominal pain/discomfort, pruritis, and bone pain were significantly correlated with V617F (β=0.676, P=0.0371; β=0.768, P=0.0241; β=0.791, P=0.0341, respectively), though these associations were not significant when all six symptoms were evaluated together (Symptom-6: β=0.315, P=0.171). There was no statistically significant correlation between V617F and Symptom-6. In addition, there was no correlation between any symptom and a germline variant in telomerase reverse transcriptase (TERT) rs2853677, identified as a novel predisposition allele for MPNs using a genome-wide association study of this cohort. Conclusion: Using a novel, web-based recruitment design combining MPN symptom assessment and genotyping of saliva samples, we identified significant correlations between 3 specific symptoms (pruritis, abdominal pain/discomfort, and bone pain) with V617F. Fatigue was also more strongly associated than other symptoms with QOL. There was no association between symptoms and TERT. This design is a powerful tool for future studies seeking to correlate symptoms with genotyping analysis. Disclosures: Hinds: 23andMe: Employment, Equity Ownership, Patents & Royalties. Barnholt:23andMe, Inc.: Employment. Kiefer:23andMe, Inc.: Employment. Do:23andMe, Inc.: Employment, Equity Ownership, Patents & Royalties. Eriksson:23andMe, Inc.: Employment, Equity Ownership, Patents & Royalties. Mountain:23andMe, Inc.: Consultancy, Employment, Honoraria, Patents & Royalties, Research Funding. Francke:23andMe, Inc.: Employment, Honoraria, Research Funding; Locus Development: Consultancy, Membership on an entity's Board of Directors or advisory committees. Tung:23andMe, Inc.: Employment. Zehnder:23andMe, Inc.: Unpaid advisor and collaborator Other. Gotlib:23andMe, Inc.: Unpaid advisor and collaborator Other. Mesa:23andMe, Inc: Unpaid advisor and collaborator Other.

Abstract Abstract 2847 Background and Purpose: Myelofibrosis (MF) is a progressive Philadelphia-negative myeloproliferative neoplasm characterized by debilitating symptoms, massive splenomegaly, and anemia, which severely impairs quality of life. When medical therapy is not effective or tolerated, splenectomy may be required to ease symptoms in patients with symptomatic portal hypertension, massive splenomegaly, and/or frequent red blood cell transfusions (Barbui et al. J Clin Oncol. 2011;29:761–770). In a recent study (Tefferi et al. Mayo Clin Proc. 2012;87:25–33) up to 27% of patients diagnosed with MF eventually underwent splenectomy. However, splenectomy is associated with limited duration of symptom response, high rates of perioperative morbidity and mortality, and acceleration of hepatomegaly. Clinical studies in patients with MF have demonstrated that ruxolitinib, an oral JAK1/JAK2 inhibitor, provides significant and durable reductions in splenomegaly, the burden of MF-associated symptoms, and also improved quality of life. In this post hoc analysis of pooled data from these studies, we determined the incidence of splenectomy in patients treated with ruxolitinib and those who received placebo or best available therapy (BAT) to evaluate whether ruxolitinib therapy may affect the need for splenectomy. Methods: This analysis included patients who participated in the ruxolitinib phase I/II trial (N=153; Verstovsek et al. N Engl J Med. 2010;363:1117–1127); COMFORT-I, a phase III, 24-month placebo-controlled trial of ruxolitinib (N=309; Verstovsek et al. N Engl J Med. 2012;366:799–807); and COMFORT-II, a phase III, 48-month randomized trial comparing the effects of ruxolitinib and BAT (N=219; Harrison et al. N Engl J Med. 2012;366:787–798). Incidence of splenectomy while on treatment or during the protocol-specified follow-up period, adjusted for differences in the duration of follow up, was calculated for patients on ruxolitinib, placebo, or BAT. Results: As a result of the crossover rules and a higher discontinuation rate on the comparator arms in the phase III studies, mean follow-up duration for placebo (0.67 years) or BAT (0.95 years) overall was substantially shorter than mean follow-up duration for ruxolitinib (1.78 years). Baseline characteristics of the 14 patients who underwent splenectomy were as follows: median age=63 years; median time since initial diagnosis=7.8 years; median spleen length (n=13): 17.0 cm (range: 0–28.0 cm); median spleen volume (in those with measurement, n=11)=2924 cm3 (range: 1203–6807 cm3); IPSS high risk=50%, intermediate-2 risk=43%, intermediate-1=7%. Among patients originally randomized and treated with ruxolitinib, the incidence of splenectomy was 1.1 events per 100 patient years (Table). For patients treated with placebo or BAT in the phase III studies, the incidence of splenectomy was approximately three times higher at 2.9 events per 100 patient years, despite the fact that patients on placebo or BAT were allowed to crossover to ruxolitinib if they had worsening symptomatic splenomegaly. Conclusions: Although limited by small numbers, results of this analysis suggest that ruxolitinib reduces the need for splenectomy in patients with MF. Because of crossover to ruxolitinib and higher discontinuation rates in placebo and BAT, follow-up duration was shorter in these treatment arms compared with ruxolitinib. Further, ruxolitinib treatment in crossover patients may have prevented progression of symptomatic splenomegaly in some patients who may have otherwise become candidates for splenectomy. Our analysis may underestimate the true incidence of splenectomy among patients not receiving ruxolitinib therapy and therefore, the relative reduction in splenectomy rate in patients receiving this therapy. Longer-term follow up will better define the splenectomy rate in ruxolitinib-treated patients. Disclosures: Verstovsek: Incyte Corporation: Research Funding. Kiladjian:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Shire: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding. Mesa:Incyte: Research Funding; Lilly: Research Funding; Sanofi: Research Funding; NS Pharma: Research Funding; YM Bioscience: Research Funding. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees. Gotlib:Incyte Corporation: Consultancy, Honoraria, Support for travel to meeting for the study or other purposes from Incyte Other. Kantarjian:Incyte: grant support Other. Sirulnik:Novartis: Employment, Equity Ownership. Peng:Incyte Corporation: Employment, Equity Ownership. Sandor:Incyte Corporation: An employee of Incyte and receiving stock options as part of his compensation Other, Employment. Harrison:Novartis: Honoraria, Research Funding, Speakers Bureau; YM Bioscience: Consultancy, Honoraria; Sanofi Aventis: Honoraria; Shire: Honoraria, Research Funding.