Citations

Abstract BACKGROUND: The presence of constitutional symptoms has been associated with increased mortality risk in myelofibrosis (MF) (Blood 2010;115(9):1703-8). New therapies exist which alleviate the severe symptom burden profile observed in MF patients but are only approved for use in those with intermediate-2 or high risk disease (N Engl J Med 2012;366:787-798). However, it has been proposed that there are patients who may benefit from symptom based treatment regardless of prognostic score (Am Soc Hematol Educ Program 2014;2014:277-286). We have recently characterized symptom score cutoffs at which patients would statistically benefit from treatment based on symptom scores alone (Scherber et. al. EHA 2016: a2250). These treatment thresholds included aMyeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPN-SAF TSS or MPN-10) total score of greater than or equal to 20, a worst individual item score of greater than 5, or a combined criteria of those with both an MPN-10 total score of greater than or equal to 20 and a worst individual item score greater than 5. This abstract represents an additional analysis of our MF cohort to better characterize the profile of patients who meet criteria for symptom-based therapy. METHODS: Patient demographics, symptom burden via the MPN-10 score (JCO 2012;30(33)4098-103), and disease traits were collected from MF patients and their physicians at a single time point during therapy. Previously we identified MPN-10 cutoffs via AkaikeÕs Information Criterion (AIC) analysis (Ecology 2014;95: 631-6), which represented the optimal model among all models specified for the data at hand to determine which patients would most benefit from symptom-directed therapy. RESULTS: Demographics. 695 MF patients without previousruxolitinib therapy were included in this analysis. Overall, of 455 patients (65.4%) fit a cutoff of having a single worst symptom item of greater than 5/10. 401 patients (57.7%) had a MPN-10 score of equal to or greater than 20. A total of 381 (54.8%) patients fit both of these criteria. A distribution of worse MPN-10 individual scores is shown in Table 1. Mean TSS score was 26.4 (SD=17.7). Symptom Criteria Associations. Demographics and disease traits: Neither mean age or age greater than 60 was significantly associated with meeting any of the symptom score cutoff criteria. Females were significantly more likely to meet any of the symptom score cutoffs (for all criteria, p=0.0003 or less). Patients with splenomegaly, particularly spleen size of greater than 15cm below the LCM, were significantly more likely than those with a normal sized spleen to meet any of the three criteria (spleen enlargement of any size p=0.014 or less; spleen greater than 15cm p=0.0114 or less). Patients who met any of the three symptom criteria tended to have a longer MPN duration, although this trend did not meet significance. A prior history of thrombosis was not associated with achieving any cutoff criterions. Symptom burden: Individuals who met the any symptom criteria were significantly more likely to have higher DIPSS prognostic risk score (for all p=0.0002 or less). Laboratory values: For those meeting criteria for a worst symptom greater than 5, mean WBC was 11.7 vs 9.1 x 109/L (p=0.025) and platelet count was 238.7 versus 329.1 (p=0.023). For those meeting criteria for a TSS greater than or equal to 20, mean WBC was 11.8 vs 9.5 x 109/L (p=0.04). For individuals meeting both criteria, mean WBC was 11.9 vs 9.5 x 109/L (p=0.034). The presence of peripheral blasts were significantly more common in patients with an individual worst symptom score greater than 5 (p=0.0364). Hemoglobin level was not significantly associated with symptom criteria for any cutoffs. CONCLUSION: Our analysis indicates that patients who would be treated based on symptom criteria are similar to patients who would be treated based on high risk features such as high DIPSS prognostic score, concerning blood count abnormalities (i.e., leukocytosis, thrombocytopenia, presence of peripheral blasts), and splenomegaly (particularly massive splenomegaly). Thrombosis history and age were not associated with criterion cutoff assignment, and it is notable that elderly age nor history of thrombosis alone would likely alter treatment choice other than anticoagulation. This data supports that JAK2 inhibitor treatment be strongly considered in patients meeting symptom based criteria. Disclosures Dueck: Bayer: Honoraria. Kiladjian:Novartis: Honoraria, Research Funding; AOP Orphan: Membership on an entity's Board of Directors or advisory committees, Research Funding. Zweegman:Celgene: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Takeda: Honoraria, Research Funding. Schouten:Sanofi: Consultancy; Novartis: Consultancy. Etienne:ARIAD: Speakers Bureau; Pfizer: Speakers Bureau; novartis: Consultancy, Speakers Bureau; BMS: Speakers Bureau. Harrison:Shire: Honoraria, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Baxaltra: Consultancy, Honoraria, Speakers Bureau; Incyte Corporation: Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau. Radia:Novartis: Honoraria; Pfizer: Honoraria. Cervantes:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Baxalta: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AOP Orphan: Membership on an entity's Board of Directors or advisory committees. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Mesa:Promedior: Research Funding; Celgene: Research Funding; CTI: Research Funding; Gilead: Research Funding; Incyte: Research Funding; Galena: Consultancy; Ariad: Consultancy; Novartis: Consultancy.

Abstract Abstract 1736 Background: Histone deacetylase inhibition (HDACi) has shown a potent inhibitory activity on the autonomous proliferation of hematopoietic cells of PV and ET patients carrying the JAK2V617F mutation (Leukemia. 2008;22(4):740–7). Hematological responses have been recorded during treatment with the HDACi givinostat in patients with PV and myelofibrosis (Blood. 2011; 118:a1748). Additionally, combinational use of givinostat and hydroxyurea (HU) have shown encouraging clinical response in PV (Br J Haematol. 2010;150:446–55). Recent laboratory studies of vorinstat-treated JAK2V617F knock-in mice have observed normalization of peripheral blood counts, markedly reduced splenomegaly and decreased mutant allele burden (Blood 2012; 119, 3779–89). Despite this evidence of hematologic response, to date no studies have evaluated specific changes in symptom burden among PV and ET patients treated with HDACi. METHODS ET and PV patients from the UK were enrolled in a non-randomized, open-label phase II multicenter study of the HDACi vorinostat (Haematologica 2011;96(s2):a1023). Patients were asked to complete the 18 item Myeloproliferative Neoplasm Assessment Form (MPN-SAF) (Blood 2011;118:401–408), 9 item Brief Fatigue Inventory (BFI) (Cancer 1999;85:1186–1196) and 30 item EORTC QLQ-C30 (J Natl Cancer Inst 1993; 85(5):365-76) at enrollment, week 12, week 24, and week 36. From weeks 1 through 24, participants were given 400mg of vorinostat daily and were observed from weeks 24 to 36. RESULTS Participant Demographics and Mutational Status: 15 PV and 10 ET patients were enrolled in the study. Median age of participants was 65 and 48% of participants were female. JAK2 mutations were present in 5/10 (50%) of ET and 14/15 (93%) of PV patients. Change in Symptom Severity with Vorinostat: Although most symptom severity changes did not reach statistical significance likely due to the small sample size, individual symptoms of headache (mean 1.6 baseline to 0.5 wk 36, mean maximum improvement 0.5 from baseline), dizziness (mean 1.6 baseline to 0.9 wk 36, mean maximum improvement 0.6 from baseline), sad mood (mean 2.6 baseline to 1.9 wk 36, mean max improvement 0.2 from baseline), and bone pain (mean 2.7 baseline to 0.8 wk 36, mean max improvement 0.7 from baseline) indicated consistent reductions in severity. Change in Symptom Incidence with Vorinostat: Non-sustained reductions in symptom incidence were seen with initiation of therapy for items of dizziness (50% baseline, 43% wk12, 55% wk 24, and 38% wk 36), numbness (65% baseline, 38% wk 12, 36% wk 24, 63% wk 36), sad mood (55% baseline, 47% wk 12, 40% wk 24, 50% wk 36), and itching (65% baseline, 50% wk 12, 40% wk 24, 75% wk 36). Change in MPN-SAF TSS Score with Vorinostat: Overall, MPN-SAF TSS did not vary significantly for the cohort over the course of the study (score change −.4 week 12, −0.5 week 24, −1.2 week 36, Figure 1). However, 9/17 participants who had a TSS of at least 6 at baseline had an overall improvement of at least 6 points (a moderate improvement) on at least one assessment after baseline. Of these, 5 of those 9 participants had an improvement of at least 10 points, which constitutes a large improvement in symptom burden based on a distributional definition of clinical significance using the standard deviation from a previous cohort. CONCLUSION This study represents the first analysis of symptom burden among PV and ET patients receiving vorinostat to date. In addition to previously identified changes in clinical and hematologic response, reductions in symptom burden including QOL and fatigue were observed in patients receiving vorinostat therapy which was most noticeable in patients with high baseline burden. The toxicity profile of vorinostat also suggests that better results might have observed if individualized assessment of clinicohematological responses including an integrated a marker for response into daily clinical practice and tailoring pharmacotherapy based on side effect profile (Leukemia. 2012;26(5):1148–9). Although further investigation among larger cohorts is needed, preliminary data is encouraging for successful therapeutic use of vorinostat in a clinical setting and with possible combinational therapy to reduce symptom burden among PV and ET patients. Disclosures: Harrison: Novartis: Honoraria, Research Funding, Speakers Bureau; YM Bioscience: Consultancy, Honoraria; Sanofi Aventis: Honoraria; Shire: Honoraria, Research Funding. Mesa:Incyte: Research Funding; Lilly: Research Funding; Sanofi: Research Funding; NS Pharma: Research Funding; YM Bioscience: Research Funding.

Abstract Background: The Philadelphia chromosome negative chronic myeloproliferativeneoplasms (MPNs) including essential thrombocythemia (ET), polycythemia vera(PV), and myelofibrosis (MF) are a group of diseases of myeloid clonal lineage with significant symptom burden. MPN patients have also been found to have a high likelihood of mood disturbance related to their MPN, including symptoms of depression and anxiety (BMC Cancer. 201616:167). To date, the relationship between disease factors and depressive symptoms among MPN patients has not been well characterized. Methods: We have previously published the results of a 70-item internet-based survey which evaluated fatigue-relieving strategies among MPN patients (Cancer. 2016 Feb 1;122(3):477-85). Surveyed data included mental health questionnaires including a measure of symptoms of depression, the PHQ-2, (Ann Fam Med. 2010. 8(4): 348-353), a measure of positive and negative moods the POMS-short form (J Nerv Ment Dis. 1979;167(10):612-4) and a measure of symptoms of depression and anxiety, the MHI-5 (J Consult Clin Psychol. 1983. 51;730-742). This abstract is a secondary analysis of data collected among this cohort. Data: Demographics A total of 1788 individuals diagnosed with an MPN participated in the survey. 1389 patients answered questions regarding mood and psychological comorbidities. Many MPN patients reportedthat they had been seen by a health provider for care or diagnosis of depression (32%), anxiety (29.5%), stress (26.2%), or grief(15.0%). Overall, 24.0% of ET, 22.2% of PV, and 22.9% of MF patients endorsed symptoms of depression based on their score of greater than or equal to 3 on the PHQ-2. Demographic and Psychosocial Correlates Younger patients were significantly more likely to have PHQ-2 score of equal to or greater than three (57.0 years vs 59.5 years, p=0.0006). Gender, race, and country of origin did not significantly correlate with screening positive for symptoms of depression. Higher BMI was associated with a higher likelihood of screening positive for symptoms of depression (BMI 26.2 vs 24.6, p=0.005). Not surprisingly, having received treatment for mood problems in the last 6 months (p<0.0001) along with medications for mood disorders (p=0.03) were significantly associated with increased symptoms of depression. Specifically, the use of psychostimulants (p<0.0001), antidepressants (p<0.0001), anti-anxiety medications (p=0.0005) and prescription pain medications (p<0.001), were significantly associated with elevated PHQ-2 score. Individuals with lower educational attainment were more likely to endorse depressive symptoms (p=0.0001) as well as those who were unable to work from home due to a medical disability (p<0.0001). Tobacco use was significantly associated with depressive symptoms (p=0.0002). Symptom and Mental Health Correlates Increased MPN-SAF TSS (MPN-10) score and all individual symptom items in the MPN-SAF were significantly associated with symptoms of depression (p<0.0001, Table 1). Increased POMS-B Subscales scores and total score along with lower MHI score was associated with positive depression screening. When asking patients what interventions they had tried to reduce fatigue, those who endorsed volunteer activities (18% vs 25.4%, p= 0.0062) and exercise (19.7% vs 32.2, p<0.0001) were significantly less likely to screen positive for symptoms of depression. Prognostic Risk Scoring Correlates For MF, PV and ET prognostic risk scoring did not significantly correlate with PHQ score (for all, P>0.005). Conclusions Depression and mood disorders among individuals with malignancy represent a particular challenge for health care providers, particularly in MPN patients who have been found to have a higher risk of depression than the general population. In our cohort, prognostic risk did not correlate with risk of depression. Based on these findings, it is critical that physicians who see MPN patients should closely monitor these patients for signs of depression and provide appropriate treatment when needed. Continued investigation into treatment of mood disorders among MPN patients is warranted, as patients may benefit from both symptom-directed therapies as well as traditional therapies. Encouragement of volunteering and exercise activities should be considered for thesepatientsas participation may be associated with improved mood status. Disclosures Harrison: Novartis: Consultancy, Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau; Shire: Honoraria, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Baxaltra: Consultancy, Honoraria, Speakers Bureau; Incyte Corporation: Honoraria, Speakers Bureau. Mesa:Galena: Consultancy; Incyte: Research Funding; Gilead: Research Funding; Novartis: Consultancy; CTI: Research Funding; Promedior: Research Funding; Ariad: Consultancy; Celgene: Research Funding.

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

Abstract MAJIC is a phase II trial of Ruxolitinib (RUX) vs Best Available Therapy (BAT) in essential thrombocythemia (ET) patients with resistance/intolerance to Hydroxycarbamide (HC) per European LeukemiaNet (ELN) criteria. Primary outcome was rate of complete hematological response (CHR) within 1 year (ELN criteria); secondary outcomes included partial HR, safety, thrombosis, hemorrhage, progression free survival (including transformation), molecular response (MR), symptom & quality of life (QOL) assessment. We present new data concerning molecular, symptom & clinical responses. Patients were stratified by JAK2V617F status, patient-reported symptoms & QOL determined using EQ5D, MDASI & MPN Symptom Assessment Form (MPN10), & compared using linear mixed models of post-baseline scores through month 12 adjusting for baseline; response was defined as ≥50% reduction in MPN10 total symptom score (TSS). JAK2/CALR/MPL allele burdens were assessed at baseline & 4 monthly. 110 patients were eligible for the modified ITT analysis, 58 (52%) & 52 (48%) in RUX & BAT arms respectively, comprising 44 males, 66 females, mean age 64.2ys, & resistant (24.5%), intolerant (51.8%) or both (22.7%) to HC. CHR was achieved in 27 (46.6%) of RUX patients vs 23 (44.2%) BAT patients (χ2 test p= 0.81). PHR occurred in 26 (44.8%) & 27 (51.9%) of RUX & BAT treated respectively. Grade 3 or 4 anemia occurred in 19% & 0% for RUX arm vs 0% (both grades) for BAT arm, grade 3 or 4 thrombocytopenia in 5.2% & 1.7% of RUX vs 0% (both grades) of BAT patients respectively. Grade 3 or 4 infections occurred in 10.3% of RUX patients vs 3.6% BAT arm. 9 RUX treated patients had 10 thrombotic events & 1 RUX patient a hemorrhage; vs 5 thrombotic & 5 hemorrhagic events in BAT patients (adjusted following central review). Transformations to post-ET MF occurred in 8 RUX vs 3 BAT treated patients, 1 RUX patient developed AML. 2 non-treatment related deaths occurred in each arm. Mean MPN-10 TSS & individual symptoms of early satiety & itching during the first 12 months were all significantly lower for RUX vs BAT (all p<0.05). Patients who achieved CHR had significantly better TSS, fatigue, inactivity, concentration problems, & MDASI symptom interference (all p<0.05) at baseline vs those without; however, scores during treatment did not appear to differ between CHR & non CHR groups after adjusting for these baseline differences. Allele burden during study & MRs (per ELN-IWG criteria Barosi Blood 2013) are shown in Table 1. Assays for JAK2 V617F were performed independently in 3 centres using qPCR (Guy's), TSCA NGS (Oxford) & amplicon-based NGS (Salisbury) & revealed Mean (range): JAK2 (Guy's): 33.2 (0.1-94.6), N=52; JAK2 (Oxford): 38.0 (0.5-92.2), N=52; JAK2 (Sal): 38.3 (0-90.0), N=50 (limited to JAK2 positive only). With Interclass Correlation Coefficient as follows ICC (Guy's v Oxford): 0.92 (95% CI 0.86-0.95) ICC (Guy's v Sal): 0.92 (95% CI 0.86-0.95) ICC (Oxford v Sal): 0.997 (95% CI 0.994-0.998). Notably MRs (n=5) only occurred with RUX treatment. There was no pattern of MR or progression with C/PHR or transformation, but 1 patient who transformed to PET MF had a complete MR. In a separate analysis baseline symptoms & QOL were not associated with JAK2, CALR, nor MPL status. Within RUX, baseline symptoms & QOL did not predict MR; however, fatigue, early satiety & abdominal discomfort (all p<0.05, Table 1) were significantly lower among those with MR vs not during treatment with a descriptively higher symptom response rate (2/4 [50%] vs 9/30 [30%]). Three non pre-specified multivariate analyses were performed to assess baseline factors influencing CHR (modelled for: treatment received, HC resistance or intolerance, white cell count, platelets, Hb & JAK2/CALR status); occurrence of ≥ grade 3 anemia or thrombocytopenia (modelled for: Hb (≥ 100g/dl) JAK2/CALR status); & transformation to PET-MF (modelled for: treatment, Hb ≤100g/dl). Only baseline Hb ≤100g/dl was significant for grade 3+ anemia (OR [95% CI]=0.17 [0.04, 0.72]), & PET-MF only occurred in patients with baseline WBC <10x109/L. This updated analysis shows that HC resistant/intolerant ET is clinically & molecularly diverse. We confirm that these patients are at high risk of thrombosis & transformation as suggested in prior retrospective studies. Molecular responses were limited to RUX & for the first time we demonstrate such responses may correlate with symptom improvement but not always with progression events. Disclosures Harrison: Shire: Honoraria, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Incyte Corporation: Honoraria, Speakers Bureau; Baxaltra: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau. Mead:Novartis: Honoraria, Research Funding, Speakers Bureau. Aliman:Novartis: Other: Institutional funding and grant for international conference. . Chen:Novartis: Other: Advisory Board. Coppell:Novartis: Other: Travel, accommodation and conference attendance. Knapper:ONO pharmaceuticals: Research Funding; Novartis: Honoraria, Other: Travel and expenses for international conferences. Ali:Novartis: Honoraria, Other: Conference sponsorship, advisory board meetings. Hamblin:Novartis: Other: Advisory Board. Dueck:Bayer: Honoraria. Cross:Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau. Mesa:Celgene: Research Funding; Promedior: Research Funding; CTI: Research Funding; Gilead: Research Funding; Incyte: Research Funding; Galena: Consultancy; Ariad: Consultancy; Novartis: Consultancy. McMullin:Novartis: Honoraria, Speakers Bureau.

Abstract Background : Polycythemia vera (PV) is a myeloproliferative neoplasm characterized by erythrocytosis, and in many cases leukocytosis and thrombocytosis. PV is driven by activating mutations in the JAK/STAT pathway, primarily JAK2V617F. For high-risk patients, a commonly used first-line therapy is hydroxyurea (HU); however, a subgroup of patients become intolerant of or resistant to HU. The phase 3 RESPONSE trial compared ruxolitinib (RUX) and best available therapy (BAT) in patients with PV who were intolerant of or resistant to HU (modified European LeukemiaNet criteria). Patients randomized in the BAT arm were permitted to cross over to receive RUX from Week 32 of the study. The results of the primary analysis comparing RUX to BAT prior to crossover have been reported, in which RUX was superior to BAT in achieving hematocrit control, reductions in spleen volume, and improvements in PV-related symptoms. This current analysis was conducted to evaluate the efficacy of RUX treatment in patients who crossed over from BAT relative to their original BAT treatment and relative to those originally randomized to RUX. Methods : Enrollment criteria included PV diagnosis, age ≥18 years, resistance to or intolerance of HU, splenomegaly, and phlebotomy requirement to control hematocrit. Patients were randomized 1:1 to receive open-label RUX 10 mg BID or BAT administered based on investigator judgment. BAT may have included HU, interferon/pegylated interferon, pipobroman, anagrelide, immunomodulators (eg, lenalidomide or thalidomide), or no medication. The protocol allowed for dose modifications (RUX, 5-mg BID increments [25 mg BID max]; BAT was adjusted per investigator judgment). Patients in the BAT group could cross over to RUX from Week 32 if they had not met the primary endpoint, or after Week 32 due to protocol-defined disease progression. The primary study endpoint was a composite of hematocrit control and a ≥35% reduction in spleen size at Week 32. Hematocrit was assessed at screening, every 2 weeks from Day 1 to Week 12, followed by every 4 weeks until Week 32, and 2, 4, 6, 8, 16, 24, and 32 weeks following crossover. Spleen volume was assessed by magnetic resonance imaging at screening and study Weeks 16, 32, 48, 64, 80 and every 32 weeks thereafter. The number of phlebotomy procedures was evaluated over time in each group. Results : A total of 110 patients were randomized to RUX and 112 to BAT; study discontinuation by Week 32 (before crossover was permitted) was 11% in both groups. However, most patients in the BAT arm crossed over to receive RUX treatment immediately after the Week 32 visit (84% between Weeks 32 and 48); only 3% of patients remained in the BAT arm compared with 85% in the RUX arm at the time of the data analysis (median 81-week follow-up). With up to 32 weeks on BAT therapy, 25% of patients in this group did not require a phlebotomy; in contrast, with up to 32 weeks on RUX, 79% of patients after crossover and 74% of patients initially randomized to RUX did not require phlebotomy. The number of phlebotomy procedures adjusted for 100 patient-years during BAT therapy was 196.8 vs 38.5 after crossover to RUX and 34.1 on randomized RUX treatment. Reduction in spleen volume from baseline at any visit occurred in 49% of patients receiving BAT, vs 73% of patients after crossover to RUX and 88% of patients initially randomized to RUX. The proportion of patients achieving at least a 35% reduction in spleen volume (best percentage change) was 1.8% during BAT treatment vs 38.5% after crossover to RUX and 60.0% during randomized RUX treatment. Conclusion : Treatment with RUX after crossover from BAT resulted in improved clinical outcomes compared with original BAT treatment. These findings support the primary RESPONSE results and further validate the efficacy of RUX in this patient population. Disclosures Kiladjian: Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, 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. Vannucchi: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. 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. Jones:Incyte Corporation: Employment, Equity Ownership. He:Incyte Corporation: Employment, Equity Ownership. Li:Novartis Pharmaceuticals : Employment, Equity Ownership. Habr:Novartis Pharmaceuticals: Employment, Equity Ownership. Verstovsek:Incyte Corporation: Research Funding.

Abstract Background Myelofibrosis (MF), polycythemia vera (PV), and essential thrombocythemia (ET) represent three of the most common Philadelphia chromosome negative myeloproliferative neoplasms (MPN). Individuals with these disorders suffer from excessive debilitating fatigue compared to age-matched controls. Although cytokine deregulation and impaired hematopoiesis contributes to the intrinsic causes of MPN-related fatigue, there may be contributory effects of underlying mood. To date few studies have prospectively evaluated the role of mood disorders on fatigue among this population. Methods A 70-item internet-based survey was developed by MPN investigators and patient/advocates and hosted by the Mayo Clinic Survey Research Center. The survey was promoted online via multiple MPN-related webpages including the MPN Forum, MPN Net, MPN Research Foundation, and MPN Voice during February/March of 2014. Surveyed data included disease demographics such as splenomegaly, thrombosis, hemorrhage transfusions, medications, and phlebotomies. The MPN-SAF (including the MPN 10), and Brief Fatigue Inventory were used to assess disease burden (Blood. 2011 14;118(2):401-8). Mental health was assessed using the Profile of Mood States (POMS-short form (J Nerv Ment Dis. 1979;167(10):612-4)), Patient Health Questionaire (PHQ-2 (Ann Fam Med. 2010. 8(4): 348–353)) and Mental Health Inventory (MHI-5 (J Consult Clin Psychol. 1983. 51;730-742)). Results Demographics: Overall 1788 MPN patients participated in the survey. Of these, 1676 consented to participate and provided additional data (answered at least 10 questions). Of these, 555 (33%) patients had ET, 651 (39.0%) have PV, and 417 (25.0%) have MF. Respondents were 68% female with a mean age of 59. Overall brief fatigue inventory score had a mean of 4.4 (range 0-10). MPN-10 score average was 28.4 (range 0-83). Psychological Comorbidities: Mental health assessments were obtained among participants. Mean PHQ-2 score was 1.6 (SD = 1.6, range 0-6.0). Twenty three percent of respondents scored greater than or equal to three on the PHQ-2 indicating a high probability of depression (mean = 1.6 (SD = 1.6, range 0-6)). Additionally, average MHI-5 score was 21.8 (SD = 4.9), with scores less than 60 likely representing a mental disorder with minimal misclassification rate (BMC Psychiatry. 2008. 19;8:10). Mean POMS-B score was 76.9 (SD=19.9, mean subscale scores: tension-anxiety 15.1, vigor-activity 6.0, fatigue-inertia 10.0, depression-dejection 15.5, confusion-bewilderment 14.3, anger-hostility 15.7). Patients frequently endorsed having being seen for or diagnosed with depression (32.0%), anxiety (29.5%), stress (26.2%), and grief (15.0%). Of participants, 22.2% had received active treatment of a mood disorder in the past 6 months. When queried on treatments of mood disorders, respondents often had received medication treatments (81.4%), counseling/therapy (40.3%), and group therapy (6.0%). Correlations: Many significant correlations were observed between MPN-SAF items and PHQ, MHI-5, and POMS-B (Table 1). When evaluating likelihood of depressive symptoms (as assessed by a PHQ), survey items including older age (p= 0.0006) and lower educational attainment (p=0.0001) were noted to have significant association with depressive symptoms . Higher BFI, MPN-10, and individual MPN-SAF scores were significantly associated with a higher likelihood of depressive symptoms (p<0.0001). Conclusions Overall many MPN patients reported having had coexisting mood disorders. The frequency of mood disturbance is likely greater than that in the general population (e.g., 11% of individuals in the primary care population have PHQ-2 greater than or equal to 3 (Ann Fam Med. 2010; 8(4): 348–353) and average control population POMS-B total mood disturbance score = 34.1 (BioPsychoSocial Medicine 2011, 5:6)). The causality of relationship between mood disorders and MPN-related fatigue severity is not entirely clear, fatigue could contribute to depressive symptoms, depression could cause fatigue, or it can be bidirectional. Thus mood disorders may represent a primary or secondary process in the disease course. Evaluation of MPN-related fatigue should be multifactorial, and should take into consideration underlying mood disorders as part of a comprehensive assessment and subsequent treatment regimen. Disclosures Harrison: Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria; CTI: Consultancy, Honoraria; Gilead: Honoraria; SBio: Consultancy; Shire: Speakers Bureau. Mesa:Incyte: Research Funding; Novartis: Consultancy; Gilead: Research Funding; Genentech: Research Funding; Promedior: Research Funding; Ns Pharma: Research Funding; Celgene: Research Funding; Lilly: Research Funding; Cti: Research Funding.

Abstract Background: PAC is an oral kinase inhibitor with specificity for JAK2, FLT3, IRAK1, and CSF1R that has demonstrated significant and sustained spleen volume reduction (SVR) and symptom control vs BAT (excluding JAK2 inhibitors) in MF pts regardless of platelet count (PERSIST-1). The PERSIST-2 study was a randomized, controlled, open-label, phase 3 trial of PAC 200 mg BID and PAC 400 mg QD vs BAT (including JAK1/JAK2 inhibitor ruxolitinib [RUX]) in pts with 10 or 20 MF whose platelet counts were ≤100,000/µL, a recognized adverse prognostic variable. Prior JAK2 inhibitor use was allowed. Methods: Pts were randomized 1:1:1 to PAC BID, PAC QD, or BAT. The co-primary efficacy endpoints were the percentages of pts achieving ≥35% SVR (MRI or CT) and ≥50% reduction in total symptom score (TSS; MPN-SAF TSS 2.0), both from baseline to Week 24. The primary objective was to compare the efficacy of pooled PAC (BID+QD) to BAT and the secondary objectives were to compare PAC BID and PAC QD individually to BAT. PK samples were collected and analyzed for PAC. Safety analyses were based on all pts exposed to study treatment of any duration (safety population); efficacy analyses were based on ITT pts with a randomization date allowing Week 24 endpoint evaluations prior to the full clinical hold* (ITT efficacy population). Results: 311 pts were randomized (107 PAC BID, 104 PAC QD, 100 BAT), 308 received study drug, and 221 were included in the ITT efficacy population (74 PAC BID, 75 PAC QD, 72 BAT). Demographics and baseline disease characteristics were generally balanced among the treatment arms (Table) and analysis populations. A total of 32 (44%) BAT pts in the ITT efficacy population received RUX as treatment at some point on study. Population PK analyses showed that the steady-state plasma levels achieved with BID were higher than with QD, however the Cmax levels were lower. A significantly higher percentage of pts in the pooled PAC arm achieved SVR ≥35% (18% [27/149]) vs the BAT arm (3% [2/72]; p=0.001; Figure 1A). 25% of PAC pts (37/149) had ≥50% reduction in TSS vs 14% of BAT pts (p=0.079; Figure 1B). In secondary analyses vs BAT, PAC BID demonstrated significant improvement over BAT for both efficacy endpoints with 22% achieving SVR ≥35% (BAT=3%; p=0.001) and 32% achieving ≥50% reduction in TSS (BAT=14%; p=0.011). The PAC QD arm had a significant SVR ≥35% (15% v 3%, respectively; p=0.017), but a similar proportion with ≥50% reduction in TSS (17% v 14%, respectively; p=0.652). More PAC pts reduced their red blood cell transfusion dependence at Week 24 (defined as a ≥50% reduction in average transfusions/month for 3 months relative to baseline) with 19% (7/37) in the PAC QD arm, 22% (8/36) in PAC BID, and 9% (3/35) in BAT. There was no significant difference observed in OS across the treatment arms (Figure 2). Hazard ratios for OS (95% confidence intervals) were 0.68 (0.30, 1.53) for PAC BID v BAT, 1.18 (0.57, 2.44) for PAC QD v BAT, and 0.61 (0.27, 1.35) for PAC BID v QD. PAC BID maintained this survival advantage vs BAT across nearly all demographic and MF-associated risk factors. During the course of the study, 10 (9%), 15 (14%), and 15 (14%) died on PAC BID, PAC QD, and BAT, respectively. The most common treatment-emergent adverse events (AEs) associated with PAC were gastrointestinal (diarrhea, nausea, vomiting) and hematologic (anemia and thrombocytopenia), and were generally less frequent for BID vs QD administration. Grade 3/4 cardiac AEs occurred in 7%, 13% and 9% of PAC BID, PAC QD, and BAT pts, respectively, and grade 3/4 bleeding AEs occurred in 14%, 7%, and 7%, respectively. Grade 3/4 bleeding AEs were associated with grade 3/4 thrombocytopenia, which was also more common in the PAC BID group. Nine pts had cardiac failure (2% PAC QD, 4% PAC BID, 3% BAT) and 1 (1%, PAC QD) had intracranial hemorrhage.* Conclusions: The PERSIST-2 study is the only randomized, controlled trial to date in pts with MF and thrombocytopenia (platelets ≤100,000/µL), allowed prior JAK2 inhibitor treatment exposure (including RUX), and allowed RUX as BAT comparator. Irrespective of prior JAK2 inhibitor treatment, both PAC arms were more effective at SVR than BAT; however, PAC BID appeared more active than QD dosing and achieved significance versus BAT for both SVR and TSS. The most frequent AEs with PAC were gastrointestinal and hematologic toxicities. *PAC on full clinical hold by the FDA on 2/8/2016 based on concerns around excess deaths and cardiac and hemorrhagic events in PERSIST-1. Disclosures Mascarenhas: Incyte: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; CTI BioPharma: Research Funding; Janssen: Research Funding; Roche: Research Funding; Promedior: Research Funding. Talpaz:CTI BioPharma: Research Funding; Pfizer: Research Funding; Incyte Corporation: Research Funding; Ariad: Other: Expense reimbursement, travel accomodation expenses, Research Funding; Gilead: Other: Travel, Accommodations, Expenses, Research Funding; BMS - Canada: Consultancy. Gerds:CTI BioPharma: Research Funding; Astra-Zeneca: Research Funding; Roche: Research Funding; Incyte: Research Funding. Stein:Incyte Corporation: Consultancy. Gupta:Incyte Corporation: Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Drummond:CTI BioPharma: Honoraria; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding, Speakers Bureau; Roche: Speakers Bureau. Granston:CTI BioPharma Corp.: Employment. Daly:CTI BioPharma Corp.: Employment. Dean:CTI BioPharma Corp.: Employment, Equity Ownership. Al-Fayoumi:CTI BioPharma Corp.: Employment, Equity Ownership. Callahan:CTI BioPharma: Employment. Singer:CTI BioPharma Corp.: Employment, Equity Ownership, Other: Leadership . Gotlib:Novartis: Other: Travel, Accommodations, Expenses; Steering Committee Chairman, Research Funding; Promedior: Research Funding; CTI BioPharma: Research Funding; Gilead: Research Funding; Incyte: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding. Jamieson:GSK: Research Funding; Johnson & Johnson: Research Funding; CTI BioPharma: Research Funding. Harrison:Novartis: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding, Speakers Bureau; CTI BioPharma: Consultancy, Honoraria, Speakers Bureau; Baxter: Consultancy, Honoraria; Shire: Speakers Bureau; Gilead: Speakers Bureau; Incyte: Speakers Bureau. Mesa:Novartis: Consultancy, Honoraria; Incyte: Research Funding; Gilead: Research Funding; CTI BioPharma: Research Funding; Celgene: Research Funding; Genetech: Research Funding; Promedior: Research Funding. Verstovsek:CTI BioPharma Corp: Research Funding.

Abstract Background We have previously reported on the high prevalence and severity of challenges with intimacy and sexuality amongst a large international cohort of MPN patients (Emanuel JCO 2012). We sought to further analyze the relationships between issues of intimacy (sexual desire and function), their relationships to MPN disease features, individual MPN symptom prevalence and severity, language, and overall quality of life. Methods Data was collected among an international cohort of patients with MPNs. Subjects completed the BFI, MPN-SAF, and EORTC QLQ-C30 instruments. Surveyed symptoms on the MPN-SAF included the patient’s perceptions of common MPN-related symptoms and overall quality of life (QOL) on a 0 (absent) to 10 (worst imaginable) scale. Specifically, the MPN-SAF sexuality item asked about “problems with sexual desire or function”. Total symptom score (TSS) was computed based on 10 symptom items using the published scoring algorithm on a 0 (all reported symptoms absent) to 100 (all reported symptoms worst imaginable) scale. Pairwise associations between the MPN-SAF sexuality item and continuous and categorical covariates were investigated using Pearson correlations and analysis of variance/t-tests, respectively. Multivariate regression models were used to investigate impact of groups of covariates on the sexuality item with the final multivariate model selected using forward regression. Results Demographics A total of 1908 MPN patients (essential thrombocythemia=799, polycythemia vera=671, myelofibrosis=432, missing=6) completed the sexuality item. Participants were of typical age (median=60, range 15-94) and gender (female=53%). Overall, 1218 subjects described sexuality related complaints (score >0) with an overall mean symptom score of 3.5 (median=2.0, SD=3.7, range 0-10); 725/1908 (38%) patients had severe sexuality related complaints (score >4). Univariate Analysis Among the QLQ-C30 functioning scales, all domains had similar statistically significant correlations (r=-.26 to -.32, all p<0.001). Among QLQ-C30 symptom scales, all QLQ-C30 symptoms displayed correlations ranging between .08 and .29 (all p<0.001). Among MPN-SAF items, the MPN-SAF sexuality item correlated most significantly with the TSS (r=.41, p<0.001), along with MPN-SAF symptoms (r=.16 to .39; all p<0.001). MPN-SAF sexuality measure significantly differed by anemia (means: absent 3.3, present 4.5; p<0.001), leukopenia (means: absent 3.4, present 4.4; p=0.01), thrombocytopenia (means: absent 3.3, present 4.5; p<0.001), red cell transfusion (means: no 3.5, yes 5.0; p<0.001), MPN subtype (ET mean 3.1, PV mean=3.6, MF mean=4.4; p<0.001) and language (means ranged from 2.4 [Swedish] to 4.6 [Chinese]; p<0.001). MPN-SAF sexuality did not significantly differ by age, gender, prior thrombosis or prior hemorrhage. Multivariate Analysis In a multivariate model of MPN-SAF sexuality containing all QLQ-C30 functioning scales, physical (p=0.001), emotional (p=0.01), cognitive (p=0.005) and social (p=0.002) functioning were all statistically significant. Numerous symptoms were also significant in a multivariate model of MPN-SAF sexuality containing all other MPN-SAF symptoms (all p<0.05; abdominal pain, inactivity, dizziness/vertigo/lightheadedness, insomnia, depression/sad mood, cough, night sweats and overall QOL). The final multivariate model based on forward regression starting with all demographics, clinical variables, and patient-reported QLQ-C30 scales and MPN-SAF items found age, language, QLQ-C30 role functioning and MPN-SAF items (insomnia, depression/sad mood, night sweats and QOL) to be significant (p<0.05). Conclusions Sexuality related complaints have been linked to both physiologic and psychologic origins and are highly prevalent within the MPN population. The results of this study congruently identified close associations between sexuality and function within emotional, cognitive and social domains. Additionally, the correlations of sexuality issues with MPN symptoms and disease features further suggest this item is a key correlate of overall functionality and quality of life. Future investigations into the causative factors and biological correlates of this complaint may assist in addressing this ongoing challenge. Disclosures: Etienne: 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; Pfizer: Membership on an entity’s Board of Directors or advisory committees; Ariad: Membership on an entity’s Board of Directors or advisory committees. Roy:Novartis, BMS: Honoraria. Harrison:Novartis: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; YM Bioscience: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Celgene: Honoraria; Shire: Speakers Bureau; S Bio: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity’s Board of Directors or advisory committees. Birgegard:Vifor Pharma: Honoraria. Mesa:Eli Lilly and Co: Research Funding; Genetech: Research Funding; Gilead: Research Funding; Incyte: Research Funding; Sanofi: Research Funding; NS pharma: Research Funding; Celgene: Research Funding.

Abstract Background:The Janus kinase (JAK) 1/JAK2 inhibitor ruxolitinib has been evaluated for patients with MF in the phase 3 COMFORT studies. In both trials, ruxolitinib prolonged OS, reduced splenomegaly, and improved MF-related symptoms and quality of life compared with controls. Here, we report the results of an exploratory pooled analysis of OS in the COMFORT studies at 5 years of follow-up. Methods: The double-blind COMFORT-I trial and the open-label COMFORT-II trial were randomized phase 3 studies that evaluated the safety and efficacy of ruxolitinib in patients with intermediate-2 (int-2) or high-risk primary MF (PMF), post-polycythemia vera MF (PPV-MF), or post-essential thrombocythemia MF (PET-MF). The comparator was placebo in COMFORT-I and best available therapy (BAT) in COMFORT-II. The ruxolitinib starting dose was 15 or 20 mg twice daily based on baseline platelet counts (100-200 and >200 × 109/L, respectively); dose modifications were permitted for safety and efficacy. Patients were allowed to cross over to ruxolitinib from the control arm for progressive splenomegaly, defined as a ≥25% increase in spleen volume from baseline (COMFORT-I) or study nadir (COMFORT-II), or select protocol-defined progression events; crossover was mandatory following treatment unblinding in COMFORT-I. OS was a secondary endpoint in both studies and was evaluated in an intent-to-treat (ITT) analysis using a Cox proportional hazard model that estimated the treatment effect stratified by clinical trial and International Prognostic Scoring System (IPSS) risk. The crossover-corrected treatment effect was estimated using a rank-preserving structural failure time (RPSFT) method. Results: Overall, 528 patients were randomized: 301 to ruxolitinib (COMFORT-I, n=155; COMFORT-II, n=146) and 227 to placebo (n=154) or BAT (n=73). All ongoing patients in the control arms crossed over to ruxolitinib by the 3-year follow-up. Patient populations were similar between the two trials and their details were previously published. In the combined ruxolitinib group, 162 patients (53.8%) had high-risk MF and 139 (46.2%) had int-2 risk MF based on IPSS criteria. At the 5-year ITT analysis, 128 patients (42.5%) died in the ruxolitinib group compared with 117 (51.5%) in the control group. The risk of death was reduced by 30% with ruxolitinib compared with control (median OS: ruxolitinib, 63.5 mo; control, 45.9 mo; HR, 0.70; 95% CI, 0.54-0.91; P=0.0065; Figure A). After correcting for crossover using RPSFT, OS advantage was more pronounced for patients originally randomized to ruxolitinib (median OS: ruxolitinib, 63.5 mo; control, 27 mo; HR, 0.35; 95% CI, 0.23-0.59; Figure B). An analysis of OS censoring patients at the time of crossover also demonstrated that ruxolitinib prolonged survival compared with control (median OS: ruxolitinib, 63.5 mo; control, 28.3 mo; HR, 0.53; 95% CI, 0.36−0.78; P=0.0013; Figure C). Among all patients treated with ruxolitinib, those with lower-risk disease had longer survival compared with those with high-risk disease (median OS: int-2, not reached [estimated, 102 mo]; high-risk, 50 mo; HR, 2.86; 95% CI, 1.95-4.20; P<0.0001; Figure D). In a subgroup analysis, OS favored ruxolitinib compared with placebo for patients with int-2 or high-risk MF (data not shown). At 5 years, median OS appeared to favor patients with int-2 (n=58) or high-risk (n=89) PMF who were originally randomized to ruxolitinib compared with historical (Cervantes et al; J Clin Oncol 30:2981-2987) controls (int-2 PMF, not reached [estimated, 70 mo] vs 48 mo; high-risk PMF, 34 vs 27 mo); OS was longer among patients with int-2 vs high-risk PMF (P=0.0003). Subgroup analyses showed that ruxolitinib provided an OS advantage regardless of age (>65 or ≤65 y), sex, disease type (PMF, PPV-MF, PET-MF), risk status (int-2 or high), JAK2V617F mutation status, baseline spleen volume (>10 or ≤10 cm), anemia, white blood cell count (>25 or ≤25 × 109L), or platelet count (>200 or ≤200 × 109/L). Conclusion: Long-term treatment with ruxolitinib up to 5 years prolonged survival in patients with MF compared with BAT or placebo. Corrections for patients who crossed over to ruxolitinib suggested that the separation between ruxolitinib and control OS curves was primarily caused by a delay in ruxolitinib treatment. The results suggest that earlier treatment with ruxolitinib may provide a greater survival advantage for patients with MF. Disclosures Gupta: Incyte Corporation: Consultancy, Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Mesa:Incyte: Research Funding; Ariad: Consultancy; Novartis: Consultancy; Celgene: Research Funding; CTI: Research Funding; Promedior: Research Funding; Galena: Consultancy; Gilead: Research Funding. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Kiladjian:AOP Orphan: Research Funding; Novartis: Research Funding. Cervantes:AOP Orphan: Membership on an entity's Board of Directors or advisory committees; Baxalta: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Sun:Incyte Corporation: Employment, Equity Ownership. Gao:Incyte Corporation: Employment, Equity Ownership. Dong:Novartis Pharmaceutical Corporation: Employment, Equity Ownership. Naim:Incyte Corporation: Employment, Equity Ownership. Gopalakrishna:Novartis Pharma AG: Employment, Equity Ownership. Harrison:Incyte Corporation: Honoraria, Speakers Bureau; Baxaltra: Consultancy, Honoraria, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; CTI Biopharma: Consultancy, Honoraria, Speakers Bureau; Shire: Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau.