Citations

Abstract Background: Pts with HR-MDS unfit for hematopoietic stem cell transplant (HSCT) have poor outcomes and limited survival with single-agent hypomethylating agent (HMA) therapy. Novel treatments that provide durable responses and clinically meaningful survival benefit for pts with HR-MDS are needed. TIM-3 is a promising target in myeloid malignancies as it regulates innate and adaptive immune cells and is expressed on leukemic stem cells (LSCs) and blasts but not normal hematopoietic stem cells. Sabatolimab (MBG453) is a novel immuno-myeloid therapy that binds to TIM-3 on immune cells, facilitating antileukemic immune activation and phagocytic killing of leukemic cells. Sabatolimab also binds to TIM-3 on leukemic cells, potentially impeding self-renewal of LSCs via inhibition of TIM3-galectin-9. In an early phase (ph) trial (NCT03066648) sabatolimab + HMA therapy showed a durable clinical benefit and was well tolerated in pts with HR-MDS (Wei, EHA 2021). Study Design and Methods: The STIMULUS immuno-myeloid clinical trial program is investigating the safety, efficacy, and durability of multiple sabatolimab-based combination therapies in pts with myeloid malignancies. Additional exploration of the mechanism of action of sabatolimab and identification of potential biomarkers predictive of response is planned. This abstract summarizes the design of the 4 ongoing STIMULUS trials in previously untreated adult pts with HR-MDS who are not eligible for intensive chemotherapy (IC) or HSCT. STIMULUS-MDS1 (NCT03946670) is an international, randomized, double-blind, placebo-controlled Ph II trial evaluating sabatolimab + HMA therapy in pts with very-high, high-, or intermediate-risk (vH/H/IR)-MDS which has completed enrollment (N=127). The primary endpoints of STIMULUS-MDS1 are complete response (CR) and progression-free survival (PFS). STIMULUS-MDS2 (NCT04266301) is an ongoing, international, randomized, double-blind, placebo-controlled, Ph III trial of sabatolimab + azacitidine (AZA) in pts with vH/H/IR-MDS or chronic myelomonocytic leukemia-2. Target enrollment is ~500 pts. The primary endpoint in this trial is overall survival (OS). Key secondary endpoints are time to definitive deterioration of fatigue; duration of RBC transfusion-free interval; and improvement of fatigue, physical functioning, and emotional functioning. Other endpoints include CR, marrow CR (mCR), partial remission (PR), PFS, and leukemia-free survival (LFS). STIMULUS-MDS2 is a trial that aims to determine if sabatolimab + HMA has a statistically significant and clinically meaningful benefit in OS and quality of life vs HMA alone. STIMULUS MDS-US (NCT04878432) is a US-based, open-label, single-arm, Ph II trial investigating sabatolimab + HMAs of investigators' choice (AZA intravenous [IV] or subcutaneous, decitabine IV or oral decitabine) in pts with vH/H/IR-MDS. Target enrollment is 90 pts. Primary endpoint is safety, which will be evaluated via incidence and severity of adverse events (AEs) and serious AEs. Secondary endpoints include CR, PFS, LFS, and OS. This trial will provide further understanding of sabatolimab + HMA therapy with additional insight into the safety and efficacy of sabatolimab + oral HMA. STIMULUS-MDS3 (NCT04812548) is an international, open-label, single-arm, Ph II trial that explores triplet therapy of sabatolimab combined with AZA and the BCL-2 inhibitor venetoclax (VEN) in pts with vH/HR-MDS. Part 1 of this trial is a safety run-in comprising 2 safety cohorts with ~6 pts receiving sabatolimab 400 mg + AZA + VEN and ~12 pts receiving sabatolimab 800 mg + AZA + VEN. Primary endpoint of part 1 is safety (dose-limiting toxicities between cycle 1 day 8 and end of cycle 2). If (both 400 and 800 mg) sabatolimab + AZA and VEN are safe, the trial will progress to an expansion cohort (~58 pts) of sabatolimab 800 mg Q4W + AZA + VEN. The primary endpoint is CR. Secondary endpoints include CR + mCR rate, overall response rate (CR + mCR + PR + hematologic improvement), OS, PFS, LFS, and event-free survival. The STIMULUS immuno-myeloid clinical trial program is investigating the efficacy, safety, and improved quality of life of multiple sabatolimab-based combination therapies in pts with myeloid malignancies. The goal of ongoing STIMULUS-MDS trials is to gain insight into the promising durable benefit of sabatolimab combination therapies in pts with HR-MDS. Figure 1 Figure 1. Disclosures Zeidan: Jazz: Consultancy; Jasper: Consultancy; Pfizer: Other: Travel support, Research Funding; AstraZeneca: Consultancy; Janssen: Consultancy; Novartis: Consultancy, Other: Clinical Trial Committees, Travel support, Research Funding; Loxo Oncology: Consultancy, Other: Clinical Trial Committees; Ionis: Consultancy; Kura: Consultancy, Other: Clinical Trial Committees; Incyte: Consultancy, Research Funding; Gilead: Consultancy, Other: Clinical Trial Committees; Genentech: Consultancy; Epizyme: Consultancy; Daiichi Sankyo: Consultancy; Geron: Other: Clinical Trial Committees; BMS: Consultancy, Other: Clinical Trial Committees, Research Funding; Cardiff Oncology: Consultancy, Other: Travel support, Research Funding; Boehringer Ingelheim: Consultancy, Research Funding; BioCryst: Other: Clinical Trial Committees; BeyondSpring: Consultancy; Astex: Research Funding; Astellas: Consultancy; Aprea: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Agios: Consultancy; ADC Therapeutics: Research Funding; Acceleron: Consultancy, Research Funding; AbbVie: Consultancy, Other: Clinical Trial Committees, Research Funding. Al-Kali: Astex: Other: Research support to institution; Novartis: Research Funding. Borate: Takeda: Membership on an entity's Board of Directors or advisory committees; Genentech: Membership on an entity's Board of Directors or advisory committees, Other: Advisory Board; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz Pharma: Research Funding; Blueprint Medicine: Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas: Membership on an entity's Board of Directors or advisory committees; incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; Rampal: Membership on an entity's Board of Directors or advisory committees; Galecto, Inc.: Consultancy; Promedior: Consultancy. Cluzeau: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel, accommodations, expenses, Speakers Bureau; Abbvie: Consultancy, Honoraria, Speakers Bureau; Agios: Honoraria; Amgen: Speakers Bureau; Jazz Pharma: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Astellas: Speakers Bureau; BMS/Celgene: Consultancy, Honoraria, Speakers Bureau; Pfizer: Other: travel, accommodations, expenses; Takeda: Other: travel, accommodations, expenses. DeZern: Taiho: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees. Esteve: Jazz: Consultancy; Novartis: Consultancy, Research Funding; Astellas: Consultancy; Abbvie: Consultancy; Bristol Myers Squibb/Celgene: Consultancy; Pfizer: Consultancy; Novartis: Research Funding. Giagounidis: Novartis: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. Platzbecker: Celgene/BMS: Honoraria; Novartis: Honoraria; Janssen: Honoraria; Geron: Honoraria; AbbVie: Honoraria; Takeda: Honoraria. Sallman: Kite: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees; Incyte: Speakers Bureau; Syndax: Membership on an entity's Board of Directors or advisory committees; Intellia: Membership on an entity's Board of Directors or advisory committees; Shattuck Labs: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy; Aprea: Membership on an entity's Board of Directors or advisory committees, Research Funding; Magenta: Consultancy. Santini: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Menarini: Membership on an entity's Board of Directors or advisory committees; BMS/Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Geron: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Astex: Membership on an entity's Board of Directors or advisory committees. Sanz: Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, and expenses, Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, and expenses, Speakers Bureau; Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, and expenses; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Helsinn Healthcare: Consultancy, Membership on an entity's Board of Directors or advisory committees; Boehringer Ingelheim: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead Sciences: Other: Travel, accommodations, and expenses. Sekeres: Novartis: Membership on an entity's Board of Directors or advisory committees; Takeda/Millenium: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees. Wei: Astra Zeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene/BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Agios: Membership on an entity's Board of Directors or advisory committees; Genentech: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Astellas: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Servier: Membership on an entity's Board of Directors or advisory committees, Research Funding; Macrogenics: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Van Hoef: Novartis Pharma: Current Employment. Nourry-Boulot: Novartis: Current Employment. Sadek: Novartis: Current Employment. Bengoudifa: Novartis Pharma AG: Current Employment. Sachs: Novartis Pharma AG: Current Employment. Sabo: Novartis: Current Employment, Current holder of stock options in a privately-held company. OffLabel Disclosure: Sabatolimab is a novel immuno-myeloid therapy targeting TIM-3 and is under investigation for the treatment of patients with myeloid malignancies

Abstract Background: Thrombotic and hemorrhagic complications are commonly encountered in uncontrolled essential thrombocythemia (ET). Both anagrelide and hydroxyurea (HU) have proven efficacious in cytoreduction as well as reducing these events and remain first line therapy for most high-risk ET patients. Independent of their role in risk-reduction, little is known about how these therapies impact patient symptomatology or quality of life. In this study, we compared the clinical and symptomatic profiles of ET patients receiving HU or anagrelide against patients with no previous experience with these agents. Methods: Data was assessed from a prospectively collected international database of ET patients in which demographics, disease features, and ET 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. ET risk scores were calculated using the IPSET scoring algorithm (Passamonti 2012). Thrombocytopenia was defined as a platelet count <100 x 10(9)/L, anemia was defined as hemoglobin<10 g/dL and leukopenia was defined as a white blood cell count <4.0 x 10(9)/L. Associations between the MPN-SAF individual symptoms were investigated using chi-square test for categorical data and ANOVA F-test for continuous variables. Results Hydroxyurea vs. HU Naive A total of 402 ET patients with active HU use were compared to 392 ET patients with no history of HU use. Patients using HU were older (63.5 years vs. 52.3 years, p<0.001) and had a greater concentration of both high risk (24.9% vs. 11.4%, p=0.001) and intermediate risk (53.9% vs 38.4%, p<0.001) patients. They also had a higher rate of prior thrombosis (29.8% vs 11.3%, p<0.001) and leukopenia (10.1% vs. 3.0%, p<0.001). No differences were noted between gender, a history of prior hemorrhage, red blood cell transfusion requirements, or the presence of anemia/thrombocytopenia. In comparing symptom profiles, no significant differences were noted between TSS or individual symptoms with the exception of slightly more severe cough in HU patients (1.5 vs. 1.1, p=0.02, Figure 1). Anagrelide vs. Anagrelide Naive A total of 49 ET patients with active anagrelide use were compared to 794 ET patients with no history of anagrelide use. Patients using anagrelide had a longer mean disease duration (8.1 years vs. 5.8 years) and were more anemic (9.1% vs. 1.2%, p<0.001). No differences were noted between age, gender, risk scores, the presence of leukopenia/thrombocytopenia, a history of prior thrombosis or hemorrhage complications or red blood cell transfusion requirements. Additionally, there were no significant differences between TSS or individual symptom items (Figure 1). HU vs. Anagrelide A total of 402 patients currently using HU were compared to 39 patients currently using anagrelide. Overall, HU users were slightly older (63.5 years vs. 55.1 years, p<0.001) with a greater population of patients meeting high risk criteria (24.9% vs. 2.8%, p=0.002) and having a history of prior thrombosis (29.8% vs. 12.8%, p=0.02). Patients receiving anagrelide had a slightly longer disease duration (8.2 years vs. 6.0 years, p=0.0446). In comparing symptom profiles, no differences were noted in TSS or individual symptom items between cohorts. Discussion In this retrospective analysis, it does not appear cytoreduction with either HU and/or anagrelide has a significant impact on ET symptom burden despite reducing vascular events. Importantly, the higher risk scores in HU patients did not translate directly into greater patient symptomatology supporting previous studies demonstrating a poor association between these two items. Prospective trials measuring ET symptom change, in the setting of randomized trials will better quantify impact of cytoreduction on symptom burden as well as quantify impact of newer agents such as interferon or jak inhibition. Figure 1. Symptom Comparisons Between HU, Anagrelide and Other Therapy Figure 1. Symptom Comparisons Between HU, Anagrelide and Other Therapy Disclosures Kiladjian: Incyte Corporation: Consultancy; Novartis: Other: Travel grant; Research Funding paid to institution (Hôpital Saint-Louis et Université Paris Diderot); Novartis: Consultancy. Zweegman:Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Harrison:Sanofi: Honoraria, Speakers Bureau; Shire: Speakers Bureau; Gilead: Honoraria; CTI Biopharma: Consultancy, Honoraria, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau. Cervantes:Sanofi-Aventis: Consultancy; Novartis: Consultancy, Speakers Bureau; CTI-Baxter: Consultancy, Speakers Bureau. Barbui:Novartis: Speakers Bureau. Etienne:ARIAD: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Other: Congress Travel/Accomodations, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau. Roy:Novartis: Consultancy, Research Funding; BMS: Consultancy, Research Funding. te Boekhorst:Novartis: Consultancy; CTI Biopharma: Consultancy. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Shire: Speakers Bureau; Novartis: Other: Research Funding paid to institution (University of Florence), Research Funding; Baxalta: Membership on an entity's Board of Directors or advisory committees. Mesa:Novartis. Research- incyte, Gilead, cti, Genentech, promedior, NS Pharma: Consultancy.

Abstract 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 <100 x 10(9)/L, anemia was defined as hemoglobin<10 g/dL and leukopenia was defined as a white blood cell count <4.0 x 10(9)/L. Associations between the MPN-SAF individual symptoms were investigated using Pearson correlations. Results Demographic and Disease Features: A total of 418 patients with (n=89) and without (n=329) thrombocytopenia completed the MPN-SAF. Patients with thrombocytopenia were slightly younger (57.4 vs. 61.0, p=0.01) with longer disease durations (11.9 years vs. 8.8 years, p=0.0489) and had a higher prevalence of primary myelofibrosis (PMF; 82% vs. 66%, p=0.01). The presence of thrombocytopenia was associated with other laboratory abnormalities including anemia (60.7% vs. 25.3%, p<0.001) and leukopenia (34.8% vs. 52.3%, p<0.001), along with the need for red blood cell transfusions (34.8% vs. 14.6%, p<0.001). Patient cohorts did not differ by gender, DIPSS risk score, history of prior thrombosis or hemorrhage. In comparing patients with severe thrombocytopenia (<50 x 10(9)/L, n=43) to those with moderate thrombocytopenia (51-100 x 10(9)/L, n=46), severe thrombocytopenia patients were more likely to have anemia (74.4% vs. 47.8%, p=0.01) and require red blood cell transfusions (51.2% vs. 19.6%, p=0.002). Symptoms Scores for individual MPN-SAF items were assessed for each subgroup. Patients with thrombocytopenia had markedly higher total symptom scores than patients without thrombocytopenia (32.8 vs. 24.1, p<0.001). Individual scores were also higher for most items (fatigue, early satiety, inactivity, dizziness, sad mood, sexuality, cough, night sweats, itching, fever, weight loss, overall QOL)[Figure 1]. No significant differences in MPN SAF TSS or individual symptom scores were observed in comparing severe vs. moderate thrombocytopenia patients. Discussion MF patients with thrombocytopenia have distinctive clinical characteristics and face a significantly more severe symptom burden. Importantly, despite thrombocytopenia being a recognized risk factor for disease advancement, no correlations are noted between patient symptomatology and risk category. In addition, patients with severe thrombocytopenia do not differ symptomatically from patients with moderate thrombocytopenia despite having more severe anemia, leukopenia and transfusion requirements. This implies that the degree of symptomatology expressed by thrombocytopenic MF patients occurs independent from the exact platelet value. Conclusion The results of this study suggest that patients with thrombocytopenia will benefit from aggressive symptomatic control, potentially from targeted agents. Figure 1. MF Symptoms in Patients With and Without Thrombocytopenia Figure 1. MF Symptoms in Patients With and Without Thrombocytopenia Disclosures Kiladjian: Novartis: Consultancy; Novartis: Other: Travel grant; Research Funding paid to institution (Hôpital Saint-Louis et Université Paris Diderot); Incyte Corporation: Consultancy. Zweegman:Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Harrison:Shire: Speakers Bureau; CTI Biopharma: Consultancy, Honoraria, Speakers Bureau; Sanofi: Honoraria, Speakers Bureau; Gilead: Honoraria; Novartis: Honoraria, Research Funding, Speakers Bureau. Cervantes:Novartis: Consultancy, Speakers Bureau; Sanofi-Aventis: Consultancy; CTI-Baxter: Consultancy, Speakers Bureau. Barbui:Novartis: Speakers Bureau. Etienne:ARIAD: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Other: Congress Travel/Accomodations, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau. Roy:BMS: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Vannucchi:Shire: Speakers Bureau; Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Baxalta: Membership on an entity's Board of Directors or advisory committees. Mesa:Novartis. Research- incyte, Gilead, cti, Genentech, promedior, NS Pharma: Consultancy.

Abstract Background: The Philadelphia chromosome negative myeloproliferative neoplasms (MPNs), including essential thrombocythemia (ET), polycythemia vera (PV) and myelofibrosis (MF) all have a time dependent risk of progression to either an advanced myelofibrotic state (post ET/PV MF) and/or to acute myeloid leukemia. The impact of disease duration upon the MPN symptom burden is not well understood, nor are the precise mechanisms of disease progression. We sought to better understand the impact of disease duration on MPN symptom burden. Methods: Symptom burden data was collected utilizing the Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) amongst MPN patients, collected at the time of an office visit in an international cohort of MPN patients as previously described (Scherber et. al.). Symptom burden assessment was a previously validated 27-item symptom burden questionnaire scored on a 0-10 scale (0= as good as it can be, 10 = as bad as it could be). The patient or provider was asked to report the time since MPN diagnosis. MPN duration was determined to be early if the diagnosis was established between 0 to 5 years ago, intermediate if the diagnosis was established between 6 to 10 years ago, and late if the diagnosis was established 11 years ago or more. Anemia was defined as a red blood cell count less than 10 g/dL, leukopenia was defined as a white blood cell count was below 4 x 109, and thrombocytopenia if the platelet count was below 150 x109. Statistical significance was calculated using ANOVA f-test and chi squared. Results: Patient demographics and disease burden: A total of 1443 patients responded to the survey, including 592 (41%) ET, 549 (38%) PV, and 302 (21%) MF patients, including 181 (60%) primary MF, 67 (22%) post-ET MF, and 54 (18%) post-PV MF. Among MF patients, mean duration of MPN diagnosis was 9 years, and mean duration MF diagnosis was 4.7 years. Among respondents, 757 fit criteria for early disease duration, 353 fit criteria for intermediate disease duration, and 333 fit criteria for late disease duration. Respondent mean age was 62 years and approximately half of respondents were female (55%). Patients with longer diagnosis duration tended to be older (p=0.009) and were most likely to have anemia (0.02), leukopenia (p=0.01), or thrombocytopenia (p=0.03). These individuals were also most likely to have a history of hemorrhage (p=0.007) or require red blood cell transfusions (p<0.001). Combined cohort symptom burden: On average among the combined cohort of ET, PV and MF patients, symptoms tended to worsen with time with this effect being significant for symptom items of fatigue (BFI, p<0.04), concentration (p=0.007), insomnia (p=0.02), sexual difficulties (p=0.002), cough (p=0.03), night sweats (p=0.002), and pruritus (p=0.02). Symptoms of early satiety (p=0.004), concentration difficulties (p=0.01), insomnia (p=0.03), sexual difficulties (p=0.02), cough (p=0.01), and night sweats (p=<0.001) had significantly higher prevalence in those with longer disease duration. Similarly, the total calculated MPN-10 score (p=0.008) and quality of life assessment (0.03) demonstrated worsened outcomes with time (Table 1). No significant differences in symptoms for the combined cohort were observed among individuals diagnosed 0 to 1 years ago compared to those with a diagnosis established between 2 and 5 years ago. Symptom burden in MPN subtypes. When evaluating specific MPN types, patients with essential thrombocythemia experienced significantly greater sexual difficulties over time (p=0.03). The severity (p=0.01) and incidence (p=0.03) of pruritus and incidence of night sweats (p<0.001) were significantly increased over time for individuals with PV. For those with MF, the severity (p= 0.01) and incidence (p=0.009) of cough also significantly increased with longer diagnosis duration. Discussion Overall, significant worsening in symptom burden can be recognized over time for individuals diagnosed with MPNs. Diagnosis may not necessarily correlate with disease duration as the timing of diagnosis may be delayed from onset of disease. Given the intent of this abstract to evaluate changes with disease duration, we did not investigate correlations between symptom burden and cytopenias. We do know that risk factors for survival in the MPNs include older age and thrombosis, however, disease duration should be investigated as an alternative marker of burden in future survival studies. Disclosures Harrison: CTI Biopharma: Consultancy, Honoraria, Speakers Bureau; Shire: Speakers Bureau; Gilead: Honoraria; Novartis: Honoraria, Research Funding, Speakers Bureau; Sanofi: Honoraria, Speakers Bureau. Kiladjian:Incyte Corporation: Consultancy; Novartis: Other: Travel grant; Research Funding paid to institution (Hôpital Saint-Louis et Université Paris Diderot); Novartis: Consultancy. Zweegman:Celgene: Research Funding; Janssen: Research Funding; Takeda: Research Funding. Barbui:Novartis: Speakers Bureau. Etienne:Novartis: Consultancy, Honoraria, Other: Congress Travel/Accomodations, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; ARIAD: Consultancy, Honoraria, Speakers Bureau. te Boekhorst:CTI Biopharma: Consultancy; Novartis: Consultancy. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Other: Research Funding paid to institution (University of Florence), Research Funding; Shire: Speakers Bureau; Baxalta: Membership on an entity's Board of Directors or advisory committees. Mesa:Novartis. Research- incyte, Gilead, cti, Genentech, promedior, NS Pharma: Consultancy.

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 2852 Background: The 18-item Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF, Scherber et al Blood 2011) given in conjunction with the 9-item Brief Fatigue Inventory (BFI, Mendoza et al Cancer 1999) is a patient-completed questionnaire for assessing symptoms in persons with MPNs. The MPN-SAF has been translated and validated in 9 languages to date. The Total Symptom Score (TSS) is computed from 10 of the most pertinent MPN-SAF items to assess symptom burden in MPN patients and to evaluate response to therapy. Psychometric properties of the TSS have been previously reported (Emanuel et al Blood 2012). The purpose of this analysis is to compare MPN-SAF symptoms and psychometric properties of the TSS across 9 languages in an international sample. Methods: Data were collected in an international cohort of subjects with MPNs. Surveyed symptoms included fatigue, early satiety, abdominal pain and discomfort, inactivity, headaches, concentration, dizziness, extremity tingling, insomnia, sexual problems, mood changes, cough, night sweats, pruritus, bone pain and fever on a 0 (absent) to 10 (worst imaginable) scale. TSS was computed using the published scoring algorithm on a 0 (all symptoms absent) to 100 (all symptoms worst imaginable) scale. Demographic and disease-related data including disease type, gender, and age had to be present to be included in analysis. Demographics were compared across languages groups using ANOVA and chi-squared tests. Symptoms and TSS were compared across language groups using a general linear model adjusting for disease type, age, and gender with post-hoc Tukey pairwise comparisons. Internal consistency and factor structure of the TSS were investigated overall and within language groups using Cronbach's alpha and principal-axis factoring analysis. Results: Subject Demographics and Disease Type: 1,851 subjects with polycythemia vera (PV N=655), essential thrombocythemia (ET N=769) and myelofibrosis (MF N=427; 286 primary MF, 61 PV-MF, 80 ET-MF) were prospectively enrolled and administered the MPN-SAF and BFI in 1 of 9 languages: English [UK] 55, English [US] 102, Italian 186, Swedish 114, German 112, French 457, Spanish 192, Dutch 236, and Chinese 397. Age (median 61, range, 15–94) and gender (55% F) were typical. Disease type and age varied across language groups (both p <0.001). MPN-SAF Symptoms and TSS: Symptom frequencies ranged from 19% (fever) to 88% (fatigue) overall with mean severities ranging from 0.4 (SD=1.3, fever) to 4.3 (SD=2.3, fatigue). Fatigue had the highest mean severity among all symptoms within each language group. Overall, mean TSS was 21.5 (SD=16.7) with the Swedish (mean=18.1, SD=15.2) and Dutch (mean=27.6, SD=17.1) cohorts reporting the lowest and highest unadjusted TSS means, respectively. When comparing symptom items across languages (adjusting for disease type, age, and gender), concentration and sexual problems had the most statistically significant pairwise differences (11 and 10, respectively, out of a possible 36) followed by dizziness and overall quality of life (9 each, out of a possible 36). No statistically significant pairwise differences were observed for abdominal discomfort, headache, extremity tingling, or insomnia. For the TSS, the Dutch cohort appeared to statistically significantly differ (all p <0.05) with all other languages except the English cohorts. All other TSS pairwise comparisons were not statistically significant. TSS Internal Consistency and Factor Structure: The TSS had excellent internal consistency overall (Cronbach's alpha 0.83) as well as within language groups (Cronbach's alpha 0.81–0.86). Overall factor analysis identified a single underlying construct among the 10 TSS items. Factor loadings ranged from 0.41 for fever to 0.73 for inactivity. A single factor solution was appropriate for each language group with factor loadings ranging from 0.18 to 0.85. Conclusion: This analysis suggests that the available translations of the MPN-SAF are generally acceptable for use in a broad context. The TSS demonstrated acceptable internal consistency and similar factor structure across all language groups. Most symptom and TSS comparisons between languages were not statistically significant, but for the few which differed, further studies are needed to evaluate whether these variances are due to disease-related factors or due to linguistic or cultural influences present in the cohorts. Disclosures: Kiladjian: Novartis: Honoraria, Research Funding; Celgene: Research Funding; Shire: Honoraria. Griesshammer: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. 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 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<0.05). Cluster 1: The “Reduced Symptom” Profile (n=421 (37%; 60% ET, 40% PV) The largest cluster, subjects had increased complaints of sexual difficulties and fatigue. There was a slightly higher proportion of subjects with ET (60%) versus PV. There were fewer lab abnormalities (28% prevalence) and less prior bleeding (3%) compared to other clusters. Spleen size was smallest of the cluster (1 cm below costal margin). Cluster 2: The “Fatigue-dominant” Group (n=286 (25%; 56% ET, 44% PV)). Subjects in this cluster were predominantly female and had relatively few laboratory abnormalities (19%) than other cohorts. They are characterized by high severity of fatigue compared to end-organ symptoms. Symptom profiles emphasize fatigue, QOL and insomnia with some end-organ complaints. The cohor 63% of the cohort. Cluster 3: The “End-Organ Complaints” Group (n=210 (18%; 49% ET, 51% PV)). Male predominant (56%), subjects had mainly macro-vascular symptom complaints including sexual difficulties, insomnia, and overall QOL, with few microvascular related symptoms (low itching/night sweats). Cluster 4: “Cognitive Complaints” Cluster (n=110 (10%; 53% ET, 47% PV)). The smallest cluster and female predominant (64%), main complaints include fatigue, insomnia, loss of concentration, numbness, and sad mood. Cluster 5: The “Highly Symptomatic” Cluster (n=114 (10%; 44% ET, 56% PV)). Subjects had many cognitive complaints and symptoms correlated with severe micro-vascular abnormalities (pruritus) and or splenomegaly. This cluster had the largest spleen sizes (mean 3 cm), the highest prevalence of prior thrombosis (29%), and highest frequency of lab abnormalities (43%). Cognitive and end-organ complaints were rated as most severe. Conclusion: This analysis offers new means of evaluating persons with PV and ET utilizing symptom clusters. Laboratory and physical abnormalities differed significantly between symptom clusters indicating that our groupings likely result from biological alterations present in specific disease phenotypes. Future studies should investigate correlations between clusters and 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.