Ewing, Joanne

PURPOSE Polycythemia vera (PV) is characterized by JAK/STAT activation, thrombotic/hemorrhagic events, systemic symptoms, and disease transformation. In high-risk PV, ruxolitinib controls blood counts and improves symptoms. PATIENTS AND METHODS MAJIC-PV is a randomized phase II trial of ruxolitinib versus best available therapy (BAT) in patients resistant/intolerant to hydroxycarbamide (HC-INT/RES). Primary outcome was complete response (CR) within 1 year. Secondary outcomes included duration of response, event-free survival (EFS), symptom, and molecular response. RESULTS One hundred eighty patients were randomly assigned. CR was achieved in 40 (43%) patients on ruxolitinib versus 23 (26%) on BAT (odds ratio, 2.12; 90% CI, 1.25 to 3.60; P = .02). Duration of CR was superior for ruxolitinib (hazard ratio [HR], 0.38; 95% CI, 0.24 to 0.61; P < .001). Symptom responses were better with ruxolitinib and durable. EFS (major thrombosis, hemorrhage, transformation, and death) was superior for patients attaining CR within 1 year (HR, 0.41; 95% CI, 0.21 to 0.78; P = .01); and those on ruxolitinib (HR, 0.58; 95% CI, 0.35 to 0.94; P = .03). Serial analysis of JAK2V617F variant allele fraction revealed molecular response was more frequent with ruxolitinib and was associated with improved outcomes (progression-free survival [PFS] P = .001, EFS P = .001, overall survival P = .01) and clearance of JAK2V617F stem/progenitor cells. ASXL1 mutations predicted for adverse EFS (HR, 3.02; 95% CI, 1.47 to 6.17; P = .003). The safety profile of ruxolitinib was as previously reported. CONCLUSION The MAJIC-PV study demonstrates ruxolitinib treatment benefits HC-INT/RES PV patients with superior CR, and EFS as well as molecular response; importantly also demonstrating for the first time, to our knowledge, that molecular response is linked to EFS, PFS, and OS.

Abstract MAJIC is a phase II trial of Ruxolitinib (RUX) vs Best Available Therapy (BAT) in polycythemia vera (PV) patients with resistance/intolerance to Hydroxycarbamide (HC). This analysis involved a primary comparison between the RUX and BAT arms for quality of life (QOL) durability over 60 months, with secondary comparisons of best QOL response within first year in complete hematologic responders (CR) vs a group of partial or no response (NR/PR). This is a unique analysis due to cross-over nature of prior studies. Patients were stratified by treatment arm with either RUX or BAT. QOL was assessed over 0-60 months using the Myeloproliferative Neoplasms Symptom Assessment Form (MPN-SAF). MPN-SAF Total Symptom Score (TSS) was computed as the average of all completed items multiplied by 10 (scale 0-100, higher score represents higher symptom burden). Estimates of change from baseline and between arm differences in change by timepoint were made using a linear mixed model with compound symmetry covariance structure, which included covariates for categorical time point, treatment arm, and the interaction between time point and treatment arm. The difference between arms in proportion of patients with best post-baseline TSS response of 50% or greater was testing using a Chi-square test. In this study, 147 of the 190 trial patients had started treatment and completed at least their baseline assessment and were included in the analysis with 39 patients completing through 60 months. Groups were comprised of 76 patients in the RUX group (31 females, 45 males, mean age 64.2 [SD 11.4]) and 71 patients in the BAT group (29 females, 42 males, mean age 64.6 [SD 11.5]). Symptom scores at baseline were similar between arms, with MPN-SAF weight loss the only statistically significant difference (BAT 0.7 [SD 1.71] vs RUX 1.7 [SD 2.83], p=0.02). Significant, durable improvements in TSS were noted in RUX patients with symptom improvements lasting a mean of 52 months. BAT patients experienced a worsening of their symptom burden with improvements back to baseline notable at 56 months (Figure 1). MPN-SAF TSS there were significant differences between treatment arms in change from baseline to months 2-32, 44, and 48 (all p&lt;0.05). In all months the trend was in the direction of larger improvement in the RUX arm, with the point estimate for difference ranging from 2.1 (at month 56) to 11.3 (at month 4) with most prominent changes occurring between months 2 and 32. Of the 80 patients with MPN-SAF TSS scores at baseline and at least one post-baseline timepoint, 13/41 (31.7%) BAT and 24/39 (61.5%) RUX patients had TSS reduction of 50% or greater in at least one time point, which was statistically significant (p=0.008). In regard to specific symptoms, there was a statistically significant between arm difference seen in over 5 timepoints for fatigue, early satiety, night-sweats, itching, bone pain, and weight loss. Comparing MPN-SAF TSS in Complete Response (CR n=51) vs Non-Responder/Partial Responders (NR/PR) (n=96) there was no difference at baseline in any of the measures at any time point. A possible limitation of this study is the potential for bias in which the patients who were lost to follow up could be different then the patients who remained in the study through all 60 months which would affect generalization, particularly at time points at the later years. The novel findings of this investigation demonstrate that Ruxolitinib ameliorates the PV symptom burden in patients resistant or intolerant to HC in a robust durable manner over at least four years, while patients receiving BAT have worsening of their symptom burden over this same time period. Figure 1 Figure 1. Disclosures Mead: Novartis: Consultancy, Honoraria, Speakers Bureau; Celgene/BMS: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria. Yap: Celgene: Honoraria; Faron Pharmaceuticals: Honoraria. Scherber: Incyte Corporation: Current Employment, Current holder of stock options in a privately-held company. Knapper: Novartis: Consultancy, Research Funding, Speakers Bureau; Astellas: Ended employment in the past 24 months, Speakers Bureau; Pfizer: Consultancy, Speakers Bureau; Jazz: Consultancy, Speakers Bureau. Drummond: Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; CTI: Membership on an entity's Board of Directors or advisory committees. McMullin: Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Other: clinical trial support, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AOP Orphan: Research Funding, Speakers Bureau. Mesa: CTI: Research Funding; AOP: Consultancy; Celgene: Research Funding; Novartis: Consultancy; Gilead: Research Funding; Pharma: Consultancy; Promedior: Research Funding; Constellation Pharmaceuticals: Consultancy, Research Funding; CTI: Research Funding; Samus: Research Funding; Sierra Oncology: Consultancy, Research Funding; Genentech: Research Funding; Incyte Corporation: Consultancy, Research Funding; Abbvie: Research Funding; La Jolla Pharma: Consultancy. Harrison: CTI BioPharma: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead Sciences: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Shire: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Geron: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Constellation Pharmaceuticals: Research Funding; Galacteo: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Roche: 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, Speakers Bureau; Incyte Corporation: Speakers Bureau; Sierra Oncology: Honoraria; Promedior: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AOP Orphan Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Keros: 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, Research Funding, Speakers Bureau.

Abstract The myeloproliferative neoplasms (MPN) polycythaemia vera (PV) and essential thrombocythaemia (ET) are associated with significant symptom burden with impaired quality of life (QoL). In the MAJIC study patients refractory/intolerant to hydroxycarbamide (HC), were randomised to treatment with ruxolitinib (Rux) or best available therapy (BAT). In this unique and comprehensive analysis we explore quality of life (QoL) outcomes in the MAJIC study using the MPN10 Self-Assessment Form (SAF) in particular using this unique dataset to explore for the first time differences between JAK2 ET vs PV, and JAK2 ET vs CALR ET at baseline and 12 months of therapy with Rux or BAT. Methods 306 patients were randomised, (190, PV and 116 ET arm) and followed for 5 years, no cross over was permitted. MPN10 SAF was assessed at baseline, 2, 4, 8 and 12 months in both arms. Equal variance two sample t-tests were used to test differences between diagnosis groups (JAK2 ET vs PV & JAK2 ET vs CALR ET) in baseline scores and 12-month change from baseline scores, here negative change from baseline indicates improvement. QoL data was also collected using MD Anderson Symptoms Inventory (MDASI) and 5 level EQ5D at the same time points as the MPN10 SAF. Results JAK2 ET vs PV 110 participants with JAK2 mutation were included in the analysis for JAK2 ET vs PV. 81 (74%) had PV and 29 (26%) had JAK2 ET; 44 patients (54.3%) with PV and 18 (62.1%) patients with ET were randomised to Rux, and 37 (45.6%) patients with PV and 11 (37.9%) with ET to BAT. Baseline mean total symptom score (TSS) was similar (JAK2 ET: 18.9. SD 18.4 and PV: 23.7, SD 17.81 (p=0.27). Mean for pruritus was 1.9 (SD 2.47) in JAK2 ET and 3.5 (SD 2.99) in PV (p=0.03). Other baseline scores were comparable: mean scores for fatigue was 3.3 (SD 3.07) for JAK2 ET vs 4.7 (SD 2.68) for PV, for early satiety was 2.6 (SD 2.78) for JAK2 ET vs 2.1 (SD 2.40) for PV, for abdominal discomfort 3.0 (SD 3.34) for JAK2 ET vs 2.0 (SD 2.78) for PV, for inactivity was 2.4 (SD 2.86) for JAK2 ET vs 3.2 (SD 2.72) for PV; for concentration problems was 2.2 (SD 2.51) for JAK2 ET vs 2.9 (SD 3.11) for PV, for night sweats was 1.6 (SD 2.20) for JAK2 ET vs 2.1 (SD 2.66) for PV, for bone pain was 1.8 (SD 2.97) for JAK2 ET vs 2.0 (SD 2.86) for PV, for fever was 0.5 (SD 1.46) for JAK2 ET vs 0.5 (SD 1.70) for PV and for weight loss was 0.3 (SD 0.73) for JAK2 ET vs 1.0 (SD 2.15) for PV (p&gt;0.05 for all). Concerning change at 12 months, mean (SD) change in TSS was -0.5 (SD 10.86) for JAK2 ET (n=21) vs -0.8 (SD 13.32) for PV (n=66) (P=0.93). Mean for individual symptom scores at 12 months were also not significantly different between the two phenotypic disease group (P&gt;0.05 for all parameters). (Fig 1, top panels). CALR vs JAK2 ET Exploring symptoms for CALR vs JAK2 ET: 45 patients were included; 9/16 (56.3%) CALR and 18/29 (62.1%) JAK2 patients were assigned to Rux (p=0.70). 10/16 (62.5%) CALR ET and 19/29 (65.5%) JAK2 ET. Baseline mean total symptom score (TSS) was similar (JAK2 ET: 18.9, SD 18.4 and CALR ET: 18.8, SD 16.99 (p=0. 0.98). All other baseline scores were comparable in this intolerant/ refractory population (p&gt;0.05 for all. Concerning change at 12 months, mean (SD) change in TSS was -0.5 (SD 10.86) for JAK2 ET vs -2.8 (SD 9.96) for CALR ET (P=0.56). Mean for individual symptom scores at 12 months were also not significantly different between the two phenotypic disease group (P&gt;0.05 for all parameters); the mean change in night sweats approached but did not reach significance similar (JAK2 ET: 0.2 (SD 1.89) and CALR ET: 1.8 (SD 3.07) (p=0. 0.06). (Fig 1, lower panels). Preliminary analysis of the MDASI and EQ5D-5L data at baseline and at 12 months shows similar results and will be presented. Conclusion This first analysis of its kind compared the symptom burden and other parameters of QoL of patients with PV and ET, resistant/intolerant to HC shows that with the exception of pruritus at baseline there were no substantial differences between JAK2 ET or PV. Equally changes in symptom burden across 12 months did not substantially differ between JAK2 ET or PV. A second analysis of JAK2 vs CALR ET also failed to show substantial differences. This data should be expanded in a larger cohort but supports a symptom continuum of JAK2 ET and PV and also JAK2 vs CALR ET. Figure 1 Figure 1. Disclosures Mead: Abbvie: Consultancy, Honoraria; Celgene/BMS: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Speakers Bureau. Yap: Faron Pharmaceuticals: Honoraria; Celgene: Honoraria. Knapper: Novartis: Consultancy, Research Funding, Speakers Bureau; Astellas: Consultancy, Speakers Bureau; Jazz Pharmaceuticals: Consultancy, Speakers Bureau; Pfizer: Consultancy, Speakers Bureau. Drummond: CTI: Membership on an entity's Board of Directors or advisory committees; BMS: 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. Mesa: Pharma: Consultancy; CTI: Research Funding; Abbvie: Research Funding; Genentech: Research Funding; Gilead: Research Funding; AOP: Consultancy; Incyte Corporation: Consultancy, Research Funding; Sierra Oncology: Consultancy, Research Funding; Novartis: Consultancy; La Jolla Pharma: Consultancy; Samus: Research Funding; Promedior: Research Funding; Constellation Pharmaceuticals: Consultancy, Research Funding; Celgene: Research Funding; CTI: Research Funding. Scherber: Incyte Corporation: Current Employment, Current holder of stock options in a privately-held company. McMullin: Celgene: 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; AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AOP Orphan: Research Funding, Speakers Bureau; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Other: clinical trial support, Research Funding. Harrison: CTI BioPharma: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: 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, Research Funding, Speakers Bureau; Promedior: 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, Speakers Bureau; Gilead Sciences: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Keros: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AOP Orphan Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Shire: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sierra Oncology: Honoraria; Constellation Pharmaceuticals: Research Funding; Incyte Corporation: Speakers Bureau; Geron: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Galacteo: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Abstract Introduction Individuals with the Philadelphia chromosome negative myeloproliferative neoplasms (MPNs) have previously been shown to experience symptoms in excess to age and comorbidity matched peers. Although numerous assessments of symptom burden and quality of life have been utilized among MPN populations, including the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30), Patient Reported Outcomes Measurement Information System (PROMIS¨) fatigue scale, and Functional Assessment of Cancer Therapy-Lymphoma (FACT-Lym) and the Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPN-10), there are currently no validated assessments of overall health. Developed by the EuroQol Group to assess heath status, the EQ-5D is an internationally validated self-assessment which may be useful in the assessment of health state among MPN patients (Annals of Medicine, 2001. 33:337-43). Methods The EQ-5D evaluates five dimensions of mobility, self-care, usual activities, pain/discomfort and anxiety/depression, on a scale from no problems to extreme problems and assesses patient reported health state via a numerical visual analogue scale (VAS) ranging from 0 to 100. The health state score is a composite score of these items ranging from 0 to 1.0, with higher scores indicating an improved health state. EQ-5D survey participants were essential thrombocythemia (ET) and polycythemia (PV) patients participating in the MAJIC United Kingdom (UK) trial. The MAJIC trial is a randomized, phase II study of best available therapy versus JAK inhibition in individuals with PV or ET who have been resistant or intolerant of cytoreduction with hydroxyurea /hydroxycarbamide. This study was one of the first Trials Acceleration Programme (TAP) trials and is funded by Leukaemia Lymphoma Research, with drug supplied by Novartis. Only baseline EQ-5D assessments taken at study enrollment were included in this analysis. Comparative analysis was preformed using the MPN-10 (J Clin Oncol.2012. 30:4098-103). Results: Participant Demographics: Sixty six patients with ET and 55 patients with PV completed the EQ-5D questionnaire. Median respondent age was 65 years old and half of respondents were female (54%). Average MPN duration was 10 years for ET and 9.2 years for PV. EQ-5D Scoring: Severe to extreme difficulties in the items of mobility, self-care, usual activities, pain/discomfort and anxiety/depression were common (Table 1).Patients with PV tended to have higher proportion of patients with severe to extreme difficulties in individual disease dimensions, higher VAS score, and worsened health state compared to their essential thrombocythemia counterparts, although these effects were not significant. Average VAS health score was 70.4 (+21.2) for ET and 66.5 (+19.6). When evaluating the health state composite score, the mean ET score was 0.74 (+0.32) and mean PV score was 0.66 (+0.28). EQ-5D Validation: The EQ-5D had excellent internal consistency (CronbachÕs alpha=0.87) and strong internal correlation. When evaluating external validity, strong correlations existed between the EQ-5D and the MPN-SAF TSS scales for dimensions of mobility, usual activities, pain and overall health state (many items with r >0.5 and p<0.001). Conclusions: The EQ-5D is a valid and accurate instrument for the brief assessment of health state among MPN patients. This instrument demonstrates excellent clinical utility in a large clinical study cohort and can be used in both clinical practice and trial settings. When comparing EQ-5D health state scores, ET and PV patients had worsened health than the general UK population age 60 to 69 (0.774; Med Decis Making. 2011.31(6)800-4), but similar health to individuals with other malignancies including breast cancer (0.760), prostate cancer (0.743), and lung cancer (0.689). Disclosures Mesa: NS Pharma: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; Incyte Corporation: Research Funding; Pfizer: Research Funding; Promedior: Research Funding; CTI Biopharma: Research Funding; Gilead: Research Funding; Genentech: Research Funding; Pfizer: Research Funding. Harrison:CTI Biopharma: Consultancy, Honoraria, Speakers Bureau; Sanofi: Honoraria, Speakers Bureau; Shire: Speakers Bureau; Gilead: Honoraria; Novartis: Honoraria, Research Funding, Speakers Bureau.

Background Interferons are recognized as active agents in the treatment of patients with high risk essential thrombocythemia (ET) or polycythemia vera (PV), both in the upfront setting as well as beyond. Several trials have shown high rates of hematologic and molecular responses with the use of interferons, however, data on direct comparison of interferon activity in patients with early disease in comparison to patients refractory or resistant to prior therapies, such as hydroxyurea (HU) are lacking. We conducted a controlled analysis of the activity of pegylated interferon alfa-2a (PEG) in two prospective parallel clinical trials conducted in these two unique patient populations. Methods The MPD-RC 111 (NCT01259817) was an international, multicenter, phase 2 open-label clinical trial that evaluated PEG therapy in patients with high risk PV and high-risk ET who were either refractory or intolerant (R/I) to HU by modified ELN criteria. The MPD-RC 112 trial (NCT01258856) enrolled patients with high risk ET/PV who were treatment-naïve (TN) (HU <3 months) and randomized them (1:1) to PEG or HU. All patients randomized to PEG were included in this analysis. Both protocols were conducted concurrently at the MPD-RC member institutions and utilized a similar primary endpoint of overall response rate (complete and partial response rates) by ELN Criteria at 12 months confirmed by the same blinded central review committee. Both studies utilized the same PEG starting dose of 45 mcg weekly and was titrated for response to a maximum of 180 mcg weekly. Secondary endpoints included safety information, impact on disease biomarkers, bone marrow (BM) response, and quality of life data. Results Patients ET: 39 TN and 65 R/I ET patients were available for this analysis. Median disease duration was 2.9 months in TN and 37.3 months in R/I patients. Baseline characteristics and demographics were similar in the two cohorts except lower baseline hemoglobin level in RI patients. (Table1A) PV: 43 TN and 50 R/I PV patients were included. Median disease duration was 2.5 months in TN and 54.8 months in R/I patients. Baseline characteristics only differed by lower frequency of phlebotomy rate in R/I patients. (Table1B) Baseline symptoms scores and quality of life were similar in TN and RI groups (Table 2) Response ET: CR/PR/ORR at 12 months were observed in 43.1%/26.2%/69.2% in R/I ET patients and in 43.6%/25.6%/69.2% in TN ET patients (p=0.99 for ORR). (Table 3, Figure 1) PV: CR/PR/ORR at 12 months were observed in 22%/38%/60% in R/I PV patients, and in 27.9%/58.1%/86% in TN PV patients (p=0.005 for ORR). (Table 3, Figure 1) Safety PEG was equally well tolerated throughout both treatment groups with treatment discontinuation due to adverse events occurring in 14.6% in TN patients and 13.9% in R/I patients. The mean (SD) dose of PEG was 102.7 (52.3) mcg in R/I ET patients and 128.7mcg (46.4) in R/I PV patients. For TN patients, mean dose was 85.7mcg (59.7) in ET and 93.5 mcg (44.0) in PV. Adverse events were consistent with historic reports of PEG use and the distribution of events was similar in R/I and TN patients. (Table 4) Conclusion This intention to treat response analysis included TN and R/I ET and PV patients with balanced baseline characteristics who received prospective therapy with PEG. Patients with ET had a higher overall response rate at 12 months that was equivalent in patients who were treatment-naïve and in patients who were intolerant or refractory to HU. By contrast, patients with PV who were treatment-naïve had a higher ORR than patients those intolerant or refractory to HU. We conclude that treatment with PEG is an effective therapeutic option both treatment naïve PV and ET as well as those previously treated with HU, however PEG as a second line agent is especially effective in ET patients. Disclosures Yacoub: Hylapharm: Equity Ownership; Agios: Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Seattle Genetics: Honoraria, Speakers Bureau; Incyte: Consultancy, Honoraria, Speakers Bureau; Ardelyx: Equity Ownership; Cara: Equity Ownership; Dynavax: Equity Ownership. Mascarenhas:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Research Funding; Roche: Consultancy, Research Funding; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Pharmaessentia: Consultancy, Membership on an entity's Board of Directors or advisory committees; CTI Biopharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Research Funding; Promedior: Research Funding; Merus: Research Funding. Mesa:AbbVie: Research Funding; Samus: Research Funding; Incyte: Research Funding; Sierra Onc: Consultancy; Genotech: Research Funding; Promedior: Research Funding; Novartis: Consultancy; Celgene: Research Funding; CTI Biopharma: Research Funding; La Jolla Pharma: Consultancy. Rampal:Agios, Apexx, Blueprint Medicines, Celgene, Constellation, and Jazz: Consultancy; Constellation, Incyte, and Stemline Therapeutics: Research Funding. Silver:PharmEssentia: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. McMullin:Daiko Sanyo: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Speakers Bureau; Italopharma: Membership on an entity's Board of Directors or advisory committees. Ewing:Novartis: Honoraria, Other: Meeting attendance sponsorship ; Bristol Myers-Squibb: Other: Meeting attendance sponsorship . O'Connell:Astex: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Shionogi: Membership on an entity's Board of Directors or advisory committees. Mead:Bristol Myers-Squibb: Consultancy; Novartis: Consultancy, Honoraria, Other: Travel/accommodation expenses, Research Funding, Speakers Bureau; CTI: Honoraria, Research Funding; Celgene: Consultancy, Research Funding; Pfizer: Consultancy. De Stefano:Alexion: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau. Baer:Astellas: Research Funding; Al Therapeutics: Research Funding; Abbvie: Research Funding; Incyte: Research Funding; Forma: Research Funding; Kite: Research Funding; Takeda: Research Funding. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees; Italfarmaco: Membership on an entity's Board of Directors or advisory committees; CTI BioPharma: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Kremyanskaya:La Jolla: Consultancy; Incyte, Celgene, Constellation, Protagonist.: Research Funding. Hexner:novartis: Research Funding. Rambaldi:Amgen: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding, Speakers Bureau; Italfarmaco: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding, Speakers Bureau; Omeros: 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, Other: travel support, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding, Speakers Bureau; Jazz: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau, travel support. Ritchie:Genentech: Other: Advisory board; Tolero: Other: Advisory board; agios: Other: Advisory board; Pfizer: Other: Advisory board, travel support; Celgene: Other: Advisory board; Jazz Pharmaceuticals: Research Funding; Celgene, Novartis: Other: travel support; AStella, Bristol-Myers Squibb, Novartis, NS Pharma, Pfizer: Research Funding; Ariad, Celgene, Incyte, Novartis: Speakers Bureau; Celgene, Incyte, Novartis, Pfizer: Consultancy. Kiladjian:Novartis: Honoraria, Research Funding; AOP Orphan: Honoraria, Research Funding; Celgene: Consultancy. Harrison:Promedior: Honoraria; Incyte: Speakers Bureau; Sierra Oncology: Honoraria; Celgene: Honoraria, Speakers Bureau; Janssen: Speakers Bureau; CTI: Speakers Bureau; AOP: Honoraria; Shire: Speakers Bureau; Roche: Honoraria; Gilead: Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau. Hoffman:Merus: Research Funding. OffLabel Disclosure: Pegylated Interferon Alfa-2a for in Patients with Polycythemia Vera or Essential Thrombocythemia

Abstract Background: Myeloproliferative neoplasms (MPN) including polycythemia vera (PV), essential thrombocythemia (ET), and myelofibrosis (MF) are clonal hemopathies characterized by burdensome symptom profiles and impaired quality of life. Treatments include pharmacologic approaches, phlebotomy, and bone marrow transplant. Outcome studies have historically focused on hematologic improvement and survival benefit. Few prospective studies have evaluated patient-reported symptoms and quality of life outcomes after standard therapy. The Myeloproliferative Neoplasm Quality of Life (MPN-QOL) Study Group aims to objectively quantify symptomatic response to standard treatments. Here we provide updated results for the prospective MPN Experimental Assessment of Symptoms by Utilizing Repetitive Evaluation (MEASURE) trial. Methods: The MEASURE trial is a prospective international cohort study evaluating responsiveness of the Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPN-SAF TSS or MPN-10) in an anticipated 480 ET, PV, and MF patients receiving non-experimental medical therapy and/or phlebotomy. Patients complete the MPN-SAF TSS (JCO 2012) for seven consecutive days at enrollment then again for seven days between 90 days and six months later. Patients also complete the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core-30 (EORTC QLQ-C30) and M.D. Anderson Symptom Inventory (MDASI) instruments at enrollment and on the first day of the second assessment. Physicians report demographic, laboratory, and clinical data. Results: Demographics To date, 340 patients have enrolled and 270 have completed both study visits. Participants include ET (60%), PV (29%), and MF (12%; including 68% primary MF, 12% post-ET, 20% post-PV) patients. Enrolled patients are 51% male. The most common therapies received prior to enrollment were aspirin (34%), phlebotomy (15%), hydroxyurea (14%), and warfarin/clopidogrel/anticoagulation (6%). The most common current MPN therapies were hydroxyurea (67%), aspirin (24%), phlebotomy (9%), and ruxolitinib (8%). Information on mutational analysis was also collected; 77% of patients have a known JAK2 V617F mutation, 3% have an MPL W515 mutation. Symptom Measures On the MPN-SAF TSS, the majority of individual symptoms assessed did not change significantly between the two assessment time points while on standard therapy. Notable exceptions were a significant decrease in weight loss (mean 2.0 vs. 1.7 on a 0=absent to 10=worst imaginable scale, p=0.005) and a significant worsening in quality of life (mean 3.6 vs. 3.8 on a 0=as good as it can be to 10=as bad as it can be scale, p=0.04). No changes were seen in other symptoms including early satiety, abdominal discomfort, night sweats, fatigue, inactivity, poor concentration, bone pain, itching, or fever. Similarly, the cumulative MPN-SAF TSS score remained stable at a mean of 24.4 over the treatment period. These findings were congruent with those observed using the EORTC QLQ-C30 instrument, with no significant changes seen in emotional, physical, role, cognitive, or social functioning. Finally, the MDASI also revealed a lack of change in either symptom severity (mean 2.7) or symptom distress (mean 3.0) scores, which remained stable over the study period. Discussion: Myeloproliferative neoplasms are associated with burdensome symptoms that significantly compromise quality of life. To date, no studies have quantified symptomatic response to standard-of-care treatments. Overall, results from the MEASURE study suggest that standard treatments have limited systematic impact on patient symptomatology over time, with no improvements in overall quality of life. However, we note the relatively low proportion of patients in this cohort treated with ruxolitinib, which has been shown previously to improve symptom burden, and this may have impacted the symptom responses seen in the group as whole; detailed responses by treatment and MPN subtype will be presented. Figure. Figure. Disclosures Dueck: Pfizer: Honoraria; Bayer: Employment; Phytogine: Employment. Ross:BMS: Honoraria; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Research Funding. Tam:Janssen: Honoraria, Research Funding; Gilead: Honoraria; AbbVie: Honoraria, Research Funding; Pharmacyclics: Honoraria, Travel funding; AbbVie: Honoraria, Research Funding; Roche: Honoraria; Beigene: Honoraria, Other: Travel funding; Pharmacyclics: Honoraria; Gilead: Honoraria; Roche: Honoraria; Beigene: Honoraria, Other: Travel funding. Radia:Novartis: Speakers Bureau; Blueprint: Consultancy. Mesa:UT Health San Antonio - Mays Cancer Center: Employment; Celgene: Research Funding; NS Pharma: Research Funding; Pfizer: Research Funding; Gilead: Research Funding; Genentech: Research Funding; Promedior: Research Funding; CTI Biopharma: Research Funding; Incyte Corporation: Research Funding; Novartis: Consultancy.

Abstract Background: Patients (pts) with polycythemia vera (PV) and essential thrombocythemia (ET) suffer from difficult MPN associated symptoms which impact quality of life (QoL). The impact of initial cytoreduction on ET/PV symptoms, resulting toxicity and QoL have not been prospectively studied. Methods: MPD-RC 112 trial (NCT01258856) randomized 168 therapy-naive (hydroxyurea [HU] <3 mo) high risk ET/PV pts (<5 years of disease) to response adjusted pegylated interferon alpha 2a (PEG) or HU. MPN symptoms, in depth toxicity assessment, and QoL were measured by two symptom instruments (MPN-SAF, EORTC QLQ-C30: baseline,3, 6, 9, and 12 mo) and toxicity questions. Blinded response review by European Leukemia Net (ELN) hematological responses (HR) was conducted at 12 months. Individual time point and longitudinal group comparisons were based on mixed models adjusting for age. Results: Patients: Of 168 randomized pts (86 HU, 82 PEG), 164 (98%) completed the survey package at baseline and 151 (HU 83%; PEG 98%) completed at least 1 survey during treatment. Median age was 61 (range 18-87) with 70 (42%) females; 81 (48%) / 87 (52%) with ET / PV; 46 (27%) had a history of a thrombosis. 119 (71%) received prior HU (up to 3 months). Baseline characteristics were balanced between arms with the exception of age (median HU 63 vs. PEG 60 yrs; p=0.02). Baseline Symptom Burden /QoL: Mean MPN-SAF Total Symptom Score (TSS), scale 0 [absent]-100 [worst imaginable] was 15.8 (SD 12.6; range 0-62.0) with means of 15.1 (SD 12.6) / 16.5 (SD 12.6) for ET / PV which were slightly lower than reported means of a previous cohort receiving any line of treatment (Scherber RM, JCO 2012). Median number of moderate (defined as score >=3) symptoms in ET patients was 3.0 and PV 4.0. Most common moderate symptoms were fatigue (65.9%), insomnia (37.2%), numbness (33.5%) , itching (29.9%), dizziness (27.4%), early satiety (26.8%) , headache (23.2%), sad mood (23.2%), inactivity (22%), concentration (20.7%). 50.6% of patients had one or more symptom with a score >=6. Mean QLQ-C30 global health status/QoL (GHS/QoL) was 70.8 (SD 21.9) - comparable to a general population (mean 71.2, SD 22.4) and better than a general cancer population (mean 61.3, SD 24.2; QLQ-C30 Reference Manual 2008). At baseline, TSS, symptoms, and QoL were similar between treatment arms. In patients with TSS >20 at baseline (highly symptomatic, n=50; ET:20, PV:30), median TSS was 28.0 (range 20.0 to 62.0); the highest scored symptom was fatigue (median=7.0), itching (median=4.5) and insomnia (median=4.0). Impact of Therapy on Symptom Burden/QoL: On HU, pts experienced worsening QoL (physical, cognitive functioning, HRQoL) and some persistent or transient worsened symptoms (inactivity, concentration (p<0.05) (Table 1)). On PEG, pts experienced worsening of fever, dyspnea, appetite loss and PEG-related symptoms including flu-like symptoms, injection site irritation, blurry vision, and visual changes (all p<0.05), but not sad mood (not corrected for antidepressants). In comparing arms, change in TSS significantly differed (p=0.01) between arms with increasing symptoms on HU vs PEG at 3 and 6 mo, but lower symptom burden at 9 and 12 mos (Figure 1). In highly symptomatic pts (with a baseline TSS > 20, n=50), improvements in weight loss, abdominal discomfort, fatigue, itching, fever, early satiety (12 m.) were observed in pts on HU. For PEG, in highly symptomatic pts, improvements were observed for overall TSS score, fatigue, inactivity, night sweats, and itching (with similar toxicities to all PEG patients). ELN Response and Symptom Burden/QoL: Among the 133 pts with 12-mo symptom data, complete hematologic response (CHR) rate was 43%. Inactivity and sad mood were worse in those patient achieving a CHR (inactivity: CHR worsening 0.68 vs PHR/NR better 0.26; p=0.03; sad mood: CHR worsening 0.67 vs PHR/NR better 0.67, p=0.002)). These latter changes were not related to higher doses utilized (in either arm), suggesting obtaining CHR may have negative effects on patient symptoms. Conclusions:In pts with a significant baseline MPN symptom burden, cytoreductive therapy has both a beneficial impact on baseline MPN symptom burden but also leads to therapy associated toxicity, although different patterns of efficacy and toxicity between HU and PEG. Achievement of a CHR in PV/ET may be associated with higher rates of drug related toxicities, and the value of achieving CHR may need further validation. Disclosures Mesa: Incyte Corporation: Research Funding; CTI Biopharma: Research Funding; Gilead: Research Funding; NS Pharma: Research Funding; Promedior: Research Funding; Novartis: Consultancy; Celgene: Research Funding; UT Health San Antonio - Mays Cancer Center: Employment; Genentech: Research Funding; Pfizer: Research Funding. Mascarenhas:Merck: Research Funding; CTI Biopharma: 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; Roche: Research Funding; Promedior: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Janssen: Research Funding. Rambaldi:Omeros: Consultancy; Roche: Consultancy; Celgene: Consultancy; Pfizer: Consultancy; Novartis: Consultancy; Italfarmaco: Consultancy; Amgen Inc.: Consultancy. Yacoub:Novartis: Honoraria, Speakers Bureau; Cara Therapeutics: Equity Ownership; Ardelyx, INC.: Equity Ownership; Inycte: Honoraria, Speakers Bureau; Seattle Genetics: Honoraria, Speakers Bureau; Dynavax: Equity Ownership. Harrison:Gilead: Honoraria, Speakers Bureau; CTI BioPharma: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau. Kiladjian:AOP Orphan: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: 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. Mead:Elstar: Research Funding; Celgene: Research Funding; ARIAD: Consultancy; Cell Therapeutics: Consultancy; Evotek: Research Funding; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Consultancy. Kessler:Sangamo: Research Funding; Octapharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novo Nordisk: Honoraria, Research Funding; Dimension Advisory boards: Membership on an entity's Board of Directors or advisory committees; Bayer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; DSMB: Membership on an entity's Board of Directors or advisory committees; Genentech: Research Funding; Biomarin: Research Funding. Kremyanskaya:Incyte: Research Funding. Rampal:Incyte: Honoraria, Research Funding; Constellation: Research Funding; Jazz: Consultancy, Honoraria; Stemline: Research Funding; Celgene: Honoraria. Hoffman:Incyte: Research Funding; Janssen: Research Funding; Merus: Research Funding; Formation Biologics: Research Funding; Summer Road: Research Funding. Dueck:Pfizer: Honoraria; Bayer: Employment; Phytogine: Employment.

Abstract Introduction HU is the treatment of choice for patients (pts) with high risk ET/PV, however, PEG has been proposed as an alternative option due to its proposed potential to modify disease course. An interim analysis of MPN-RC 112 (Blood 2016 128:479;) did not reveal a difference in PR/CR rates between HU and PEG therapy after 12 months in the first evaluable 75 pts treated. Here we present the results and long-term follow-up of all pts participating in this pivotal study [NCT01259856]. Methods MPN-RC 112 was a randomized, open label, phase 3 clinical trial comparing HU and PEG in pts with high risk ET/PV. Pts were treated for up to 12 months to achieve PR or CR (ELN/IWG-MRT response criteria). Pts who achieved a PR/CR continued therapy for up to a maximum of 6 years. Minimum follow up was 1 year from the time the last pt was randomized. The primary objective was to compare the CR rate following HU vs. PEG at 12 months with 3 month confirmation. Secondary objectives included a comparison of toxicity and tolerability; PR rates; incidence of specific pre-defined toxicities and tolerance to therapy; impact of therapy on key biomarkers; survival and incidence of myelodysplastic syndrome, myelofibrosis, or leukemic transformation; and incidence of major cardiovascular events. Bone marrow pathologic responses were evaluated by central blinded expert review at baseline, 12, 24 months and end of study. Results The study accrued 168 pts; 86 were randomized to HU and 82 to PEG. A summary of pt baseline characteristics by treatment arm is shown in Table 1 and were well balanced between the treatment arms except for median age which was higher in the HU arm (p=0.02). Median duration of follow up was 89.9 weeks (range, 0 to 292.3) and the median treatment duration was 86.0 weeks (range, 0 to 287.3). At 12 months, the overall response rate (ORR= PR+CR) was 69.8% and 78% for HU and PEG, respectively (p=0.22). Figure 1 shows the distribution of responses stratified by disease type. At 24 months, 59 pts were on treatment with an ORR of 22/25 (88%) for HU and 31/34 (91%) for PEG. When considering all 106 pts who were eligible to receive treatment for 24 months (due to study closure), the ORR was 22/54 (40.7%, PR: 11 (20.4%), CR: 11 (20.4%)) for HU and 31/52 (59.6%, (PR: 15 (28.9%), CR: 16 (30.8%)) for PEG, p=0.04. Best ORR at any time on study was seen in 70.9% and 81.7% of HU and PEG treated pts, respectively, p=0.10. The median maximum change from baseline spleen volume was -6% (-100.0 - +53.8) in 112 evaluable pts and was similar between arms, p=0.99. Bone marrow morphologic responses are shown in Table 2 and the best response (CR) seen at any time on study for ET treated with HU was 52% (12/23) vs PEG 32% (8/25) and for PV treated with HU 19% (6/31) vs PEG 6% (2/34). Cytogenetic analyses at diagnosis were available in 86% (144/168). An abnormal karyotype was seen in 15% (22/144). Five PV and one ET pt lost their chromosomal abnormalities: 3 after one year (HU=1, PEG=2) and three after two years of therapy (HU=2, PEG=1). AE information is available for 162 pts (HU: 80; PEG: 82) (Table 3). Six pts randomized to HU never received treatment due to study withdrawal prior to initiation of treatment. Sixty pts had a grade 3 or higher event [HU: 22 (27.5%) and PEG: 38 (46.3%)]. 28 PV pts had a grade 3/4 [HU: 10 (24.4%) and PEG: 18 (41.9%)]. Four pts had a grade 4/5 event [HU: 3 (7.3%) and PEG: 1 (2.3%)]. 32 ET pts had a grade 3/4 [HU:12 (30.8%) and PEG:20 (51.3%)]. Two pts had a grade 4/5 event [HU:1 (2.6%), PEG:1 (2.6%)]. Additional outcomes of interest on study include one death attributed to new diagnosis of lung cancer (HU:1), progression to myelofibrosis (HU:1), vertebral artery occlusion (HU:1), and cerebral vascular accident (PEG:1). Reasons for study discontinuation are shown in Table 4. The effect of therapy on symptom burden and quality of life will be presented in a companion abstract (Mesa et al). The impact of mutation status on therapeutic outcome as well as the molecular responses will be presented at the meeting. Conclusion The final analysis of MPN-RC 112 revealed that the CR rates in pts with high risk ET/PV treated with PEG and HU at 12 and 24 months were similar. PEG was associated with a higher rate of grade 3/4 toxicity. Each drug appeared equally capable of modifying the natural history of high risk ET/PV based upon their effects on spleen size, karyotypic abnormalities, histopathological parameters and the low incidence of thrombotic complications and disease evolution in both arms. Disclosures Mascarenhas: Novartis: Research Funding; Promedior: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Research Funding; Merck: Research Funding; CTI Biopharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding. Rambaldi:Amgen Inc.: Consultancy; Pfizer: Consultancy; Novartis: Consultancy; Italfarmaco: Consultancy; Omeros: Consultancy; Roche: Consultancy; Celgene: Consultancy. Harrison:Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; CTI BioPharma: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Gilead: Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau. Kiladjian:AOP Orphan: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: 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. Mead:Bristol-Myers Squibb: Consultancy; Elstar: Research Funding; Celgene: Research Funding; ARIAD: Consultancy; Evotek: Research Funding; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Cell Therapeutics: Consultancy. Kessler:Genentech: Research Funding; Sangamo: Research Funding; Bayer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Biomarin: Research Funding; Octapharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; DSMB: Membership on an entity's Board of Directors or advisory committees; Novo Nordisk: Honoraria, Research Funding; Dimension Advisory boards: Membership on an entity's Board of Directors or advisory committees. Kremyanskaya:Incyte: Research Funding. Rampal:Stemline: Research Funding; Incyte: Honoraria, Research Funding; Constellation: Research Funding; Jazz: Consultancy, Honoraria; Celgene: Honoraria. Mesa:CTI Biopharma: Research Funding; Novartis: Consultancy; Genentech: Research Funding; Promedior: Research Funding; UT Health San Antonio - Mays Cancer Center: Employment; Pfizer: Research Funding; Celgene: Research Funding; Incyte Corporation: Research Funding; Gilead: Research Funding; NS Pharma: Research Funding. Dueck:Pfizer: Honoraria; Bayer: Employment; Phytogine: Employment. Hoffman:Incyte: Research Funding; Formation Biologics: Research Funding; Merus: Research Funding; Janssen: Research Funding; Summer Road: Research Funding.

Abstract Background: Patients (pts) with polycythemia vera (PV) and essential thrombocythemia (ET) suffer from disease related events linked to risk of vascular events, splenomegaly, progression to myelofibrosis/acute leukemia, and disease related symptoms arising from both elevated cytokines and issues of vascular flow. Impact of front line therapy on ET/PV symptoms has not been reported in a systematic fashion. Methods: MPD-RC 112 trial (NCT01258856) enrolled cytoreductive therapy naïve (hydroxyurea [HU] <3 mo) pts with high risk ET or PV within 3 years of diagnosis. Pts were randomized (1:1, stratified by ET vs PV) to either response adjusted pegylated interferon alpha 2a (PEG) or HU. MPN symptoms, treatment toxicities, and quality of life (QoL) were measured by the MPN-SAF and EORTC QLQ-C30 at baseline and 3, 6, 9, and 12 mo. PEG related toxicities were assessed with 5 questions on PEG arm only. European Leukemia Net (ELN) complete hematological responses (CHR) at 12 mo were determined by central blinded review. Individual time point and longitudinal group comparisons were based on mixed models adjusting for age. T-tests were used to compare change scores at 12 mo between pts with and without CHR. Results: Patients: MPD-RC 112 enrolled 168 pts from 9/2011 to 7/2016, with 75 pts included in the interim analysis. 73 (97%; HU 37, 95%; PEG 36, 100%) completed surveys at baseline of which 66 (90%; HU 30, 81%; PEG 36, 100%) completed at least 1 survey during treatment. Median age was 60 (range 19-84) with 32 (44%) females; 30 (41%) / 43 (59%) with ET / PV; 19 (26%) had a history of thrombosis; and 16 (22%) had palpable spleen. Baseline characteristics where balanced between arms with the exception of age (median age: HU 66, PEG 54; p<0.001). Baseline Symptom Burden/QoL: Mean MPN-SAF Total Symptom Score (TSS, scale 0 [absent]-100 [worst imaginable]) was 15.4 (SD 12.5; range 0-52.2) with means of 12.6 (SD 11.7) / 17.3 (SD 12.7) for ET / PV which were somewhat better than reported means of a previous cohort receiving any line of treatment (ET mean 18.7, SD 15.3; PV mean 21.8, SD 16.3; Emanuel RM, JCO 2012). Symptoms (scale 0 [absent]-10 [worst imaginable]) with the highest prevalence (score >0) included fatigue (65/73, 89%) and insomnia (47/73, 64%). The symptom with the lowest prevalence was fever (8/72, 11%). Mean QLQ-C30 global health status/QoL (GHS/QoL) was 73.3 (SD 19.1) which is comparable to a general healthy population (mean 71.2, SD 22.4) and better than a general cancer population (mean 61.3, SD 24.2; QLQ-C30 Reference Manual 2008). TSS, symptoms, and QoL did not differ between arms. Impact of Therapy on Symptom Burden/QoL: On HU, pts initially experienced worsening of TSS, fatigue, early satiety, itching, bone pain, and fever (all p<0.05) with some symptoms returning to baseline after 6 mo (Table 1). On PEG, pts experienced improved abdominal pain and discomfort, but worsening of headache, cough, injection site irritation, blurry vision, and vision change (all p<0.05). Sad mood did not worsen on PEG, although this may be confounded by concurrent use of mood stabilizers. Concentration problems on PEG were significantly worse at 9 mo (p=0.04). Both arms experienced worsened QoL (MPN-SAF single item: HU p=0.009, PEG p=0.003). In comparing between arms, TSS significantly differed (p=0.009) with higher symptoms on HU vs PEG at 3 and 6 mo, but lower symptoms at 9 and 12 mo (Figure 1). Similar descriptive profiles were observed for most individual symptoms; however, the only symptom profiles which significantly differed between arms was early satiety (p=0.03). ELN Response and Symptom Burden/QoL: Among 62 pts with symptom and response data at 12 mo, CHR rate was 37% (23/62). Change in sad mood and sexuality were the only significant differences between pts with and without CHR regardless of arm though in the unanticipated direction (sad mood: mean change 1.5 vs -0.8, p<0.001; sexuality: mean change 2.33 vs 0.3, p=0.03). Conclusions: PEG was associated with an initial decrease in MPN symptom burden when compared to HU. However, with longer duration of therapy, this superiority dissipated. Patient-reported PEG toxicities worsened over time. On both arms, symptom worsening was observed in pts achieving an ELN CHR, possibly leading to the observed negative impact on mood and sexuality. Future research on the impact of PEG on disease progression and molecular features will be important to assess whether increased side effects with PEG are justified. Disclosures Mesa: CTI: Research Funding; Celgene: Research Funding; Promedior: Research Funding; Gilead: Research Funding; Incyte: Research Funding; Galena: Consultancy; Ariad: Consultancy; Novartis: Consultancy. Harrison:Incyte Corporation: Honoraria, Speakers Bureau; Baxaltra: Consultancy, Honoraria, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Shire: Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau. McMullin:Novartis: Honoraria, Speakers Bureau. Yacoub:Alexion: Honoraria; Seattle Genetics: Consultancy, Honoraria, Speakers Bureau; Incyte: Consultancy, Honoraria, Speakers Bureau. Kiladjian:Novartis: Honoraria, Research Funding; AOP Orphan: Membership on an entity's Board of Directors or advisory committees, Research Funding. Mead:Novartis: Honoraria, Research Funding, Speakers Bureau. Kessler:Pfizer: Consultancy; Octapharma: Consultancy, Research Funding; Novo Nordisk: Consultancy, Research Funding; Grifols: Consultancy; Genentech: Consultancy, Research Funding; Biogen: Consultancy; Bayer: Consultancy, Research Funding; Baxalta: Consultancy, Research Funding; LFB: Other: Member of DSMB. Ritchie:Pfizer: Honoraria; Novartis: Honoraria; Arian: Speakers Bureau; Celgene: Speakers Bureau; Incyte: Speakers Bureau. Schlenk:Pfizer: Honoraria, Research Funding; Amgen: Research Funding. Mascarenhas:Promedior: Research Funding; Janssen: Research Funding; CTI Biopharma: Research Funding; Novartis: Other: DSMB , Research Funding; Roche: Research Funding; Incyte: Other: Clinical Trial Steereing Committee, Research Funding.