Citations

Abstract Abstract 3816 Background: The hypomethylating agent (HMA) azacitidine (AZA) significantly improves survival compared to conventional care regimens for patients (pts) with “higher risk” MDS (including both Int-2 & High-Risk according to IPSS) (Lancet Oncol 10:223, 2009 – first presented Dec 2007); a more recent trial of the HMA decitabine (DEC) vs. best supportive care in pts with similar IPSS failed to show a significant survival advantage (JCO 29:1987, 2011 – first presented Dec 2008). Since 2006 the immunomodulatory drug lenalidomide (LEN) has been FDA-approved for treatment of anemia in lower-risk MDS pts & deletion of chromosome 5q (Del5q). However, no phase III survival data have been presented with LEN in patients with higher risk MDS, nor is it an expert consensus 1st-line treatment recommendation in higher risk setting (NCCN Guidelines 2011). We sought to evaluate the change in 1st-line treatment preference with these 3 approved agents for higher risk MDS among AHOP's from 2006–2010 in relation to pertinent survival data as it became available. Methods: Between 2006–10 we studied time dependent prescribing preferences of n=1960 AHOP's in a prospective annual research series. Approx. 330–450 individual AHOP's participated in any given year. AHOP demographic data was available from 2007–10 (n=1510); they were predominantly male (77%), working in Community setting (79% vs. 21% Academic), & in small group practice (≤5 providers −59%, including 18% “solo practice”). All regions were represented (NE 23%; SE 22%; Central 19%; SW 13%; West 23%). Most (57%) were >10yrs out from training, and only 18% were <5yrs out from training. A total sample was studied using an extensively tested, live, case-based, market research vehicle to anonymously acquire data. AHOP's were presented with a scenario of an older pt with higher risk MDS (High-Risk 2006–09; Int-2 in 2010) & specific cytogenetic abnormalities, then indicated their preferred treatment from up to 10 relevant available/emerging 1st-line therapeutic options. In each, the scenario was of a pt age 63 yrs (2006–08) or 68–70 yrs (2009–10); with symptomatic anemia & pancytopenia; no response to darbepoietin; with RAEB-2 - excess Bone Marrow blasts 11% (2006–09) to 16% (2010); complex (2006–09) or normal cytogenetics (2010); and both without and then with Del5q in same scenario (2008–10). The distribution of treatment choices was compared over time & according to Del5q status using a chi-square test. Results are shown in Table below. In NON-Del5q scenario, a clear & significant shift toward greater AZA preference by almost 2-fold (from 40% to 78%) was apparent after 2007 (P<0.0001). For same scenario With Del5q (2008–2010), treatment preferences changed significantly over time (P<0.0001), with lower 1st-line AZA and greater DEC & LEN preference (the latter >40% after 2008). In addition, a marked and significant increase in 1st-line LEN preference was observed when AHOP's were presented with the same higher-risk scenario each yr but With-Del5q vs. NON-Del5q (p<0.0001). For “Non Del 5q” vs. “With Del 5q” scenarios, p-values result from a chi-square test, testing for any difference in the distribution of treatment choices over time. *(p<0.0001) - LEN With-Del5q vs. NON-Del5q in higher-risk scenario each year, 2008–2010. Conclusions: Significant changes in 1st-line treatment preferences of AHOPs for pts with higher-risk MDS are apparent in the findings from 2008–10, the time frame following the availability of randomized phase III data demonstrating a survival advantage for AZA therapy. When the presence of a Del5q abnormality is added to the same higher-risk scenario, treatment preferences change dramatically with a significantly increased preference for LEN (despite no available ph III survival data supporting this approach) and for DEC (despite a “negative” ph III trial). These findings suggest important educational gaps concerning the available phase III survival data supporting first line prescribing preferences for patients with higher risk MDS. Efforts to address this gap via evidence-based approaches are warranted. Disclosures: Foran: Celgene: Honoraria; Xcenda: Honoraria. Williams:Xcenda: Honoraria; Celgene: Consultancy, Honoraria, Independent DSMB member, Research Funding. Willey:Xcenda: Employment; Celgene: Business relationship; Eisai: Business relationship. Green:Xcenda: Employment; Celgene: Business relationship; independent DSMB; Eisai: Business relationship.

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.

Abstract Abstract 468 The requirement for BAFF and BAFF-R in normal human and murine B cells is well studied, but there is also significant evidence to suggest that BAFF plays an important role in malignant B cell proliferation and survival. Serum BAFF levels are elevated in patients with non-Hodgkin lymphoma (NHL) and high BAFF levels correlate with aggressive disease and a poor response to therapy. There is also increasing genetic evidence suggesting an association between the development of human disease and genetic variation in genes encoding BAFF and its receptors. Mutations in TNFRSF13B (TACI) were identified in patients with familial common variable immunodeficiency (CVID) and IgA deficiency and we have found that single nucleotide polymorphisms (SNP) in TNFSF13B (BAFF) are associated with elevated BAFF levels and risk for developing NHL. To build upon these findings we sequenced BAFF and its receptors; TNFSF13B, TNFRSF13B, TNFRSF17(BCMA), and TNFRSF13C (BAFF-R) in NHL patients to identify novel genetic variants that may be associated with NHL risk. Among 40 individual samples (20 controls and 20 follicular lymphoma (FL) cases) that were bi-directionally sequenced we identified a heterozygous cytosine to thymidine transition in 1 patient specimen at position 475 (C475T) of TNFRSF13C. The C475T transition encodes a missense substitution of tyrosine for histidine in codon 159 (H159Y) in the highly conserved cytoplasmic tail of BAFF-R, adjacent to the TRAF3 binding motif PVPAT. We next expanded our analysis of BAFF-R H159Y and analyzed NHL tumor biopsies for the presence of the mutation. 4/41 (10%) follicular lymphomas (FL), 2/42 (5%) diffuse large B cell lymphomas, 1/22 (5%) lymphoplasmacytic lymphomas (LPL), and 1/24 (4%) mucosal associate lymphoid tissue lymphomas carried the heterozygous mutation. The BAFF-R H159Y mutation was not detected in any of the normal control DNA from healthy donors (n=100). Given its close proximity to the TRAF3 binding site in the cytoplasmic domain of BAFF-R we first wanted to determine if the H159Y mutation altered BAFF induced signaling. We generated cell lines that express HA-tagged wildtype BAFF-R, BAFF-R with the H159Y mutation, or BAFF-R with an ablated TRAF3 binding site as a negative control. Analysis of cells expressing H159Y BAFF-R demonstrates that this mutation results in increased BAFF-R-mediated NFκB1 and NF-κB2 activation. The enhanced signal activated by BAFF-R H159Y is coupled with a several fold increase in TRAF3, TRAF2, and TRAF6 recruitment to BAFF-R and increased IgM production. We further demonstrate that recruitment of TRAF6 to BAFF-R is not unique to the mutant H159Y BAFF-R, but is also an important and necessary feature of BAFF-R signaling in normal B cells. Collectively, our data identify a novel lymphoma-associated mutation in BAFF-R and describe exciting new aspects of BAFF-R signaling that are important for understanding normal B cell homeostasis and function, as well as pathogenic BAFF-R contributions to human disease. Disclosures: No relevant conflicts of interest to declare.

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: 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. Few studies have evaluated patient-reported outcomes during treatment with non-experimental pharmacological regimens. Aims: The Myeloproliferative Neoplasm Quality of Life (MPN-QOL) Study Group aims to objectively quantify MPN symptom severity, frequency and quality of life at baseline and throughout treatment with non-experimental therapies utilizing the Myeloproliferative Neoplasm Symptom Assessment Form - Total Symptom Score (MPN-SAF TSS; JCO 2012). In this abstract, we provide updated results for the prospective international cohort trial currently in active enrollment: the MPN Experimental Assessment of Symptoms by Utilizing Repetitive Evaluation (MEASURE) trial. Methods: This study aims to recruit 180 international ET, PV, and MF (including primary MF and post-ET or post-PV MF) patients receiving non-experimental medical therapy and/or phlebotomy. Patients complete the MPN-SAF for seven consecutive days at enrollment and repeat the survey for an additional seven consecutive days between 90 days and six months. Patients also complete the European Organisation for Research and Treatment of Cancer (EORTC) and M.D. Anderson Symptom Inventory (MDASI) instruments at enrollment and on the first day of the second assessment. At visits, physicians acquired demographic, laboratory, physical examination, and radiographic data. Descriptive statistics were used to summarize data. Results: Clinical Data The MEASURE trial opened for enrollment in 2012 and remains in recruitment phase with 15 participating international sites. To date, 39 patients have been enrolled and 25 have completed both study visits. Participants include ET (28%), PV (24%), and MF (48%; 50% primary MF, 8% post-ET, 42% post-PV) patients. The majority of patients are male (64%) and of expected age (mean 69.3, range 39-89) for the disorders. Seventeen percent had prior thrombosis, 9% required red blood cell transfusion, and none reported prior splenectomy or hemorrhage. Mean hematologic measures included hemoglobin 13.2 g/dL, WBC count 11.4 x109/L, ANC 8.5 x109/L, and platelets 514 x109/L. Therapies received prior to enrollment included aspirin (n=16), hydroxyurea (n=11), phlebotomy (n=8), warfarin/clopidogrel/anticoagulation (n=8), erythropoietin (n=2), and interferon (n=1). The most common current MPN therapies were hydroxyurea (n=9), aspirin (n=9), interferon (n=4), and phlebotomy (n=2). Symptom Assessment In comparing MPN-SAF TSS mean symptom scores, all symptoms except bony pain improved between the first and second visits, including fatigue, early satiety, abdominal discomfort, inactivity, concentration, night sweats, itching, fever, weight loss, and overall quality of life (Figure1). Total MPN-SAF TSS scores improved from a mean of 32.3 to 25.9. On the EORTC, mean scores for physical, role, emotional, and social functioning improved from the first to the second visit (Figure 2). Cognitive functioning showed a slight decline. Global health status measure improved from 60.2 to 72.9. On the MDASI, symptom severity scores decreased from 3.6 to 2.8 from the first to second visit (Figure 3). Symptom distress measure decreased from 4.1 to 3.0. Discussion: Interim results from the MEASURE trial demonstrate that standard, non-experimental treatment regimens offer improvement in quality of life-related symptoms on multiple patient-reported survey instruments including the MPN-SAF TSS, EORTC QLQ-C30, and MDASI. Updated data including symptom correlations and mutational analysis to be presented at the 2016 ASH conference. Disclosures Ross: Novartis Pharmaceuticals: Honoraria, Research Funding; BMS: Honoraria. Radia:Novartis: Honoraria; Pfizer: Honoraria. McMullin:Novartis: Honoraria, Speakers Bureau. Cargo:Novartis: Honoraria; Celgene: Honoraria, Research Funding. Sekhar:Novartis: Research Funding. Mesa:Gilead: Research Funding; CTI Biopharma: Research Funding; Galena: Consultancy; Ariad: Consultancy; Incyte: Research Funding; Novartis: Consultancy; Celgene: Research Funding; Promedior: Research Funding.

Abstract Background: Cytoreductive therapy with hydroxyurea (HU) has been considered first line therapy for patients with high risk polycythemia vera (PV) and essential thrombocythemia (ET) since the results of the PVSG-08 trial demonstrated thrombotic risk reduction (Fruchtman SM et al 1997) for PV and PT1 for ET (Harrison CN et al 2005). Although HU is well tolerated by most patients and has been shown to reduce thrombotic risk in this setting, concern regarding the leukemogenic potential of this oral ribonucleotide reductase inhibitor balanced by the observation of molecular responses with interferon-α (IFN-α) led us to compare the clinical response and tolerability of pegIFN-α (PEG) and HU in a global, randomized, phase III trial. Methods : MPD-RC 112 trial (NCT01258856) enrolled patients with high risk (age >60 years, history of thrombosis, extreme thrombocytosis, symptomatic splenomegaly, uncontrolled cardiovascular risk factors), newly diagnosed (<5 years), WHO defined ET/PV that were treatment naïve (HU <3 months) and randomized (1:1) to PEG or HU. The primary endpoint was complete hematologic response (CHR) rate by European LeukemiaNet (ELN) criteria between the arms after 12 months of therapy. A planned interim analysis based on intent-to-treat with testing boundaries for efficacy and futility was conducted after 75 patients were on study for 12 months. Response assessment by ELN criteria were conducted by blinded review by 4 investigators (JM, RAM, AY, RH). Intent-to-treat analysis was conducted for efficacy endpoints (HU n=39; PEG n=36). Safety analysis included all patients who received treatment (HU n=36; PEG n=36). Results: Patients: The MPD-RC 112 trial involved 24 centers in 6 countries; enrollment began 09/2011 and concluded 7/2016 prior to full accrual due to study drug availability with 168 patients enrolled (Table 1 for 75 patients in the interim analysis). There was no imbalance between arms with respect to history of thrombosis, erythromelalgia, diabetes, hypertension, but age was significantly older on HU. This remained true when analyzing by ET/PV disease strata with the exception of diabetes which was slightly imbalanced within the PV cohort (HU 5/23, 22%; PEG 0/21, 0%; p<0.05). Response: CHR and PHR were observed in 13 (33%) and 14 (36%) patients for an overall response rate (ORR) of 69% (27/39) for HU, and 10 (28%) and 19 (53%) for an ORR of 81% (29/36) for PEG (CHR comparison p=0.60 based on z-test which did not cross either testing boundary). 10 patients randomized to HU were not evaluable for 12-month response due to never initiating treatment (n=3) or early study discontinuation for AEs (n=1), patient withdrawal (n=5), or treatment non-compliance (n=1). 3 patients were not evaluable for response on PEG due to early study discontinuation for AEs (n=1), physician decision (n=1), or patient withdrawal (n=1). Excluding patients who never initiated treatment did not impact the primary endpoint comparison (HU 13/36, 36%; PEG 10/36, 28%; p=0.45). For ET, CHR and PHR were observed in 7 (44%) and 4 (25%) patient on HU, and 6 (40%) and 6 (40%) for PEG (CHR comparison p=0.83). For PV, CHR and PHR were observed in 6 (26%) and 10 (44%) patients on HU, and 4 (19%) and 13 (62%) for PEG (CHR comparison p=0.58). Normalization of spleen by palpation at 12 months was seen in 2/7 (29%) and 5/7 (71%) of the HU and PEG treated patients with palpable spleen at baseline, respectively. Among 38 PV patients, rate of phlebotomy use at 12 months was 0/18 (0%) vs 5/20 (20%) on HU and PEG (p=0.02). From baseline to best score through 12 months, 9/28 (32%) and 12/34 (35%) patients with data on HU and PEG, respectively, had a ≥50% reduction in MPN-SAF Total Symptom Score (p=0.79). Toxicity: No Grade 4 AEs occurred in either treatment arm. Overall, Grade 3 AEs occurred in 5/36 (14%) HU patients and 16/36 (44%) PEG patients (Grade 3 hematologic: 4/36 [11%] HU vs 8/36 [22%] PEG; Grade 3 non-hematologic: 5/36 [14%] HU vs 16/36 [44%] PEG). See Table 2 for Grade 3 AEs regardless of attribution occurring in >10% of patients in either arm. Conclusions: This interim analysis does not show a clear difference in primary endpoint of CHR between HU and PEG. A comparative analysis of the quality of life and symptom burden will provide further insight into the tolerability of these agents (Mesa et al ASH 2016). The final results of this pivotal trial will provide necessary data required to firmly establish the optimal first line therapy for patients with high risk ET/PV. Disclosures Mascarenhas: CTI Biopharma: Research Funding; Janssen: Research Funding; Promedior: Research Funding; Roche: Research Funding; Novartis: Other: DSMB , Research Funding; Incyte: Other: Clinical Trial Steereing Committee, Research Funding. Mesa:Celgene: Research Funding; Promedior: Research Funding; CTI: Research Funding; Gilead: Research Funding; Incyte: Research Funding; Galena: Consultancy; Ariad: Consultancy; Novartis: Consultancy. Yacoub:Alexion: Honoraria; Seattle Genetics: Consultancy, Honoraria, Speakers Bureau; Incyte: Consultancy, Honoraria, Speakers Bureau. Harrison:Baxaltra: Consultancy, Honoraria, Speakers Bureau; Incyte Corporation: 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. Vannucchi:Novartis: 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:Incyte: Honoraria. Ritchie:Celgene: Consultancy, Other: Travel, Accomodations, Expenses, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Novartis: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding, Speakers Bureau; Ariad: Speakers Bureau; Pfizer: Consultancy, Research Funding; Astellas Pharma: Research Funding; Bristol-Meyers Squibb: Research Funding; NS Pharma: Research Funding. Schlenk:Amgen: Research Funding; Pfizer: Honoraria, Research Funding.

Abstract Abstract 3972 Background: The treatment paradigm for myeloma has undergone a dramatic shift in the past decade with the introduction of the novel agents and their application at every stage of the treatment. We and others had previously shown that survival of patients with myeloma had improved in the earlier half of the last decade and attributed this to a combination of novel therapies as well as increased use of stem cell transplant. It is not clear if this momentum in improving survival has been maintained. We examined the survival trends of patients with newly diagnosed myeloma seen within the past decade to examine this question. Patients and Methods: We studied 1056 patients with newly diagnosed myeloma, who were seen at Mayo Clinic between January 1, 2001 and December 31, 2010; who were seen within 30 days of their diagnosis. For examination of the time trends, we grouped the time interval into two five year periods, 2001–2005 and 2006–2010. Survival was estimated using Kaplan Meier method and survival curves were compared by log rank test. Impact of various prognostic factors was evaluated using Cox proportional hazards test. Results: The median age at diagnosis was 65 (range; 22–92), and 59% were male. The median estimated follow up for the entire cohort was 4.6 years (95% CI; 4.4, 4.9) and 57% of the patients were alive at last follow up. The median overall survival (OS) for the entire cohort was 5.4 years (95% CI; 5, 6.3). The overall survival for patients in the 2001–2005 group was 4.6 years compared with not reached for the 2006–2010 cohort (P< 0.001). The five-year estimated OS was 48% for the earlier group compared with 66% for the latter group. The estimated 1-year survival was 90% for the recent cohort compared with 83% for the earlier cohort, suggesting improvements in the early mortality. Interestingly, the improvement was predominantly seen in the older age group (>65 years; 49%). The 5-year survival of the older patients improved significantly from 31% (2001–2005) to 56% (2006–2010) (P<0.001). In contrast, among younger patients (≤65 years of age), the 5-year survival improved only marginally from 63% (2001–2005) to 73% (2006–2010) (P=NS). One or more novel agents (Lenalidomide, thalidomide or bortezomib) were used as part of initial therapy in 631 (62% of 1021 in whom treatment data was available). The OS among of this group was 7.3 years (95% CI; 5.9, NR) compared with 3.8 years (95% CI; 3.1, 4.6). In a multivariate model that included both use of novel agent and the year group, only the novel agent use was associated with improved survival suggesting that the improvement in the survival is related to the increased use of novel agents in the initial therapy. No significant differences were observed between the groups in terms of conventional prognostic factors. Conclusions: The current results confirm continued improvement in the overall survival of patients, even within the last 10 year period, and highlight the impact of initial therapy with novel agents. Most importantly, we demonstrate that the improved survival has primarily benefited older patients. Our study highlights that urgent need for additional new agents to provide further survival improvement for younger patients, and in order achieve a cure for this disease. Disclosures: Kumar: Merck: Consultancy, Honoraria; Celgene: Research Funding; Millennium: Research Funding; Novartis: Research Funding; Cephalon: Research Funding; Genzyme: Research Funding. Dispenzieri:Celgene: Research Funding; Millennium Pharmaceuticals, Inc.: Research Funding; Janssen Research & Development: Research Funding. Gertz:Binding Site: Honoraria.

Abstract Abstract 1861 Idiopathic Bence Jones Proteinuria (Smoldering Monoclonal Light-Chain Proteinuria), first reported in 1982, is an asymptomatic plasma cell proliferative disorder associated with an elevated risk of progression to symptomatic MM or amyloidosis (AL). We defined it as the presence of a monoclonal light chain in the urine ≥200 mg/24h, absence of an intact immunoglobulin M protein (IGH expression) in the serum and no evidence of MM, AL or other related plasma cell proliferative disorders. Following approval by our Institutional Review Board, we searched a computerized database and reviewed the records of all patients seen at Mayo Clinic within 30 days of the recognition of a monoclonal light chain (Bence Jones protein) in the urine from January 1, 1960 through June 30, 2004. Patients with end-organ damage at diagnosis resulting from the plasma cell proliferative disorder (including MM or AL), or who had received chemotherapy or had a nephrotic syndrome were excluded. Follow-up included review of each patient's medical record at Mayo Clinic, as well as review of death certificates for patients who died. Patients were sent letters of inquiry if they had not visited Mayo Clinic in the preceding year. The risks of progression to MM and AL were compared to those expected on the basis of Surveillance, Epidemiology and End Results (SEER) rates for MM in Iowa and the incidence of AL in Olmsted County, Minnesota. One-hundred and one patients fulfilled the criteria for diagnosis during the 44-year period (1960–2004). The median age at diagnosis was 67 years (range 18–90 years), and only 2% were < 40 years old. Seventy-three percent were male. The urine M protein ranged from 200 mg/24h to 4.7 g/24h (median value, 500 mg/24h); 29% had > 1 g/24h. Kappa light chain accounted for 50% while the remaining 50% were lambda. Fifty-seven (56%) had a monoclonal light chain in the serum on immunofixation. Concentrations of uninvolved (normal, polyclonal or background) immunoglobulins were reduced in 62%. Eighty-eight percent of patients died during follow-up. During 900 person years of follow-up, 29 patients developed symptomatic MM (relative risk, 140.3; 95% CI, 93.9–201.5) and an additional 9 patients developed AL (relative risk, 104.4; 95% CI, 47.8–198.4). Four patients had both multiple myeloma and AL amyloidosis. The cumulative probability of progression to active MM or AL was 19% at 5 years, 31% at 10 years and 42% at 15 years. The factors associated with progression to MM or AL included size of urine M protein, percentage of bone marrow plasma cells, serum free light chain ratio < 1/100 or > 100, serum creatinine and reduction of all 3 uninvolved immunoglobulins. We conclude that patients with Idiopathic Bence Jones Proteinuria (Smoldering Monoclonal Light-Chain Proteinuria) are at risk for the development of MM or AL and must be followed indefinitely. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 1803 Poster Board I-829 Background Plasma cell proliferative disorders are monitored by a variety of methods. Serum protein electrophoresis (SPEP) and/or urine PEP M-spike quantitation are commonly assessed in patients with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and multiple myeloma (MM) to determine disease progression, response, or relapse. Serum immunoglobin (Ig) concentrations can be quantitated when the M-spike is large or if the migration is obscured within the SPEP beta fraction. Serum FLC quantitation provides a rapid indicator of response, will detect the rare occurrence of FLC escape, and will allow disease monitoring in the absence of a measurable serum or urine M-spike. The International Myeloma Working Group (IMWG) has recommended that the serum and urine M-spike should be used to monitor disease, and that FLC quantitation should be used only if there is no measurable disease by electrophoresis and if the monoclonal FLC concentration is greater than 10 mg/dL in the context of an abnormal FLC K/L ratio. We have studied serial samples in clinically stable patients in order to assess the total variability (analytic and biologic) of these assays and to confirm the IMWG recent recommendations. Methods Serial data from stable MGUS patients (n=35) were identified by the availability of all 3 serum test results (M-spike, Ig, FLC) in at least 4 serial samples that were obtained 9 months to 5 years apart and whose serum M-spikes varied by less than 25%. For MM (n=60) and SMM (n=48) the samples were within 9-15 months and serum M-spikes varied by less than 0.5 g/dL. Among the 60 MM, 48 SMM, and 35 MGUS patients, there were 23, 41, and 18 patients with measurable disease by serum M-spike (i.e. M-spike >1 g/dL); 19, 10, and 10 patients with an evaluable FLC (i.e. monoclonal FLC > 10 mg/dL and an abnormal FLC ratio); and 5, 5, and 1 patient with an evaluable urine (i.e. M-spike > 200mg/24 hr). The FLC data was analyzed as the involved FLC concentration (iFLC), the difference between the involved and uninvolved FLC concentration (dFLC), and the FLC K/L ratio (rFLC). The coefficients of variability (CV) were determined for each methodology in each patient sample set, and the average CVs were determined. Igs were quantitated by immunonephelometry using a Siemens BNII and Siemens reagent sets; kappa and lambda FLC were quantitated using a Siemens BNII and Freelite reagent sets from The Binding Site; M-spikes were quantitated using Helena SPIFE SPE and reagent sets. Results The CVs for the Ig quantitation, SPEP M-spike, FLC quantitation, and urine M-spike in each of the patient groups are listed in the table: Our laboratory's interassay analytic CV for replicate samples are 4-5% for Ig quantitation, 6-8% for SPEP M-spikes, 6-7% for FLC quantitation, and 5-7% for urine M-spikes. The analytic CVs of the methods are similar, but the total (analytic + biologic) CVs are very different. The samples have been selected by restricting the variability of serum M-spike values; when we apply the same criteria to the IgG quantitation, the IgG total CV comes closer to the serum M-spike CVs. The remaining differences, however, may be due to biologic variability contributed by polyclonal Ig. The total CV for iFLC is similar to the urine M-spike CV and suggests a previously unrecognized large biologic CV for serum FLC. The iFLC and dFLC CVs were comparable but were smaller than the rFLC CV. Conclusion The variability of the serum and urine M-spike, Ig, and FLC measurements confirm the IMWG recommendations for patient monitoring. If a patient has a measurable M-spike >1 g/dL, then the serum M-spike should be followed. If there is no measurable disease, then the iFLC can be monitored, provided that the rFLC is abnormal and the iFLC concentration is >10 mg/dL. Although the number of patients with evaluable urine M-spikes in this study is small, larger studies may confirm the utility of serum FLC compared to urine M-spike for monitoring patients with monoclonal gammopathies. Disclosures No relevant conflicts of interest to declare.

OBJECTIVES: Eosinophilic esophagitis (EoE), a chronic food allergic disease, lacks sensitive and specific peripheral biomarkers. We hypothesized that levels of EoE-related biomarkers captured using a 1-hour minimally invasive Esophageal String Test (EST) would correlate with mucosal eosinophil counts and tissue concentrations of these same biomarkers. We aimed to determine whether a 1-hour EST accurately distinguishes active from inactive EoE or a normal esophagus. METHODS: In a prospective, multisite study, children and adults (ages 7–55 years) undergoing a clinically indicated esophagogastroduodenoscopy performed an EST with an esophageal dwell time of 1 hour. Subjects were divided into 3 groups: active EoE, inactive EoE, and normal esophageal mucosa. Eosinophil-associated protein levels were compared between EST effluents and esophageal biopsy extracts. Statistical modeling was performed to select biomarkers that best correlated with and predicted eosinophilic inflammation. RESULTS: One hundred thirty-four subjects (74 children, 60 adults) with active EoE (n = 62), inactive EoE (n = 37), and patient controls with a normal esophagus (n = 35) completed the study. EST-captured eosinophil-associated biomarkers correlated significantly with peak eosinophils/high-power field, endoscopic visual scoring, and the same proteins extracted from mucosal biopsies. Statistical modeling, using combined eotaxin-3 and major basic protein-1 concentrations, led to the development of EoE scores that distinguished subjects with active EoE from inactive EoE or normal esophagi. Eighty-seven percent of children, 95% of parents, and 92% of adults preferred the EST over endoscopy if it provided similar information. DISCUSSION: The 1-hour EST accurately distinguishes active from inactive EoE in children and adults and may facilitate monitoring of disease activity in a safe and minimally invasive fashion.